Gold in the East Murchison Mineral Field, the Mines, the Builders and the Companies
Five mines produce gold in Western Australia's East Murchison Mineral Field, and three ASX companies with projects in the field are working toward first gold, one of them at a plant in another field. This Insight sets out the geology, the mining history, who owns each mine on 11 October 2026, and the dates that come next.
The cover photograph is of construction at Youanmi and is reproduced from Rox Resources [R53]
READING THE SERIES Gold Regions Series, Release 1
A page with no link is not yet published. That includes the Samso News piece, so this page carries no link back to it. |
A NOTE ON THE VOCABULARY AND THE SOURCES Technical terms are explained where they first appear and are collected in a vocabulary box at the end. A marker such as [R1] points to the numbered source in the reference list. Where two sources give different figures for the same thing, both are quoted with their source and neither is preferred. Gold is measured in troy ounces. Neither Noel Ong, who writes for Samso, nor Samso holds shares in any company named in this Insight. The tables shorten ounces to oz, thousand ounces to koz, million ounces to Moz, million tonnes to Mt, grams a tonne to g/t and million tonnes a year to Mtpa. |
The East Murchison Mineral Field is one of the areas the Western Australian Government uses to administer mining titles. It covers the country around Wiluna, Leinster and Sandstone, in the northern part of the State's goldfields (Fig 1). It was proclaimed as a goldfield in 1895 [R2].
Five mines in the field produce gold today. Jundee and Thunderbox belong to Northern Star Resources (ASX: NST). Bellevue belongs to Bellevue Gold (ASX: BGL). Penny belongs to Ramelius Resources (ASX: RMS). Agnew belongs to Gold Fields, which is not listed on the ASX, so it is named here for context only.
Three more companies are each the subject of a Samso Research workup, which is Samso's long study of a single company. They are Rox Resources (ASX: RXL) at Youanmi, Horizon Gold (ASX: HRN) at Gum Creek and Brightstar Resources (ASX: BTR) at Sandstone. This series labels each of them a near-term producer, meaning a company with a published feasibility study, the engineering and cost study for a proposed mine, and a stated date for first gold. Brightstar's label rests on a project outside this field. Section 6.00 sets out what each label rests on.
This Insight is the East Murchison page of Samso's Gold Regions Series. It covers what the field is, the rocks that hold the gold, what was mined and when, who owns each mine on 11 October 2026, and the dates each company has given for what comes next.
All prices in this piece are as at the close of ASX trading on 9 October 2026. Global prices for gold and the Australian dollar are taken at the same time.
WHAT THIS PIECE COVERS 1.00 THE EAST MURCHISON MINERAL FIELD AND ITS DISTRICTS What a mineral field is, where this one is, and how it relates to the Murchison. 2.00 THE ROCKS THAT HOLD THE GOLD The geology in plain English, and why some of the ore is hard to treat. 3.00 GOLD MINING HISTORY OF THE EAST MURCHISON What was found, what was mined, and why most mines stopped at least once. 4.00 WHO PRODUCES GOLD IN THE EAST MURCHISON TODAY Northern Star, Bellevue Gold and Ramelius, with Gold Fields named for context. 5.00 WILUNA MINING AND WESTERN GOLD RESOURCES A plant that is suspended, a float in progress, and a small project waiting on a mill. 6.00 THE NEAR-TERM RULE AND THE THREE COMPANIES How Samso labels a company, and the three companies side by side. 7.00 ROX RESOURCES AND YOUANMI The study, the money, the build, and the risks the workup lists. 8.00 HORIZON GOLD AND GUM CREEK The study, the decision due in 2027, and the going concern note. 9.00 BRIGHTSTAR RESOURCES AND SANDSTONE Why the label rests on Laverton, and what Sandstone still needs. 10.00 THE GOLD PRICE AND INTEREST RATES The price in two currencies, the bank targets, Samso's view and the rate rises. Each company's stated timing, and the risks. |
1.00 — THE EAST MURCHISON MINERAL FIELD AND ITS DISTRICTS
An administrative area declared beside the Murchison Goldfield in 1895
A mineral field is an area declared by the Western Australian Government for administering mining titles. The State is divided into these fields. The name East Murchison Mineral Field is the department's, and this Insight uses it [R1].
The field began as the East Murchison Goldfield. The proclamation was signed on 29 May 1895 and was printed in the Government Gazette of 5 July 1895 [R2]. Its boundary description starts from the southernmost corner of the Murchison Goldfield and runs along that goldfield's eastern side. The Murchison Goldfield was the older one, and the East Murchison was declared on its eastern edge.
The name Murchison still causes confusion for that reason. Today's Murchison Mineral Field is a separate field to the west. The department's boundary file gives it districts at Meekatharra, Cue, Day Dawn and Mount Magnet [R1]. Investors and companies often say the Murchison for the whole region, and several companies in this Insight describe their projects that way. Samso plans to cover the Murchison Mineral Field itself in a later release.
The East Murchison has three districts. A proclamation of 1 June 1904 created the Black Range District and the Lawlers District from 1 July 1904 [R3]. The Wiluna District is not in that proclamation, and Samso did not find the date it was created. Black Range is the western district and holds Sandstone and Youanmi. Gum Creek is at its northern edge, on the boundary with the Wiluna District. Lawlers is the eastern district and holds Agnew, Bellevue and Thunderbox. Wiluna is the northern district and holds Wiluna and Jundee.
Fig 1 is Samso's map of the field. It was compiled from the department's boundary file and from MINEDEX, the department's database of mines and mineral deposits, which lists 2,073 gold sites inside the boundary [R1]. The dots on Fig 1 show that those sites are not spread evenly. They follow the narrow greenstone belts described in section 2.00.
2.00 — THE ROCKS THAT HOLD THE GOLD
Two blocks of old crust and the greenstone belts on them
The field is on the Yilgarn Craton. A craton is a piece of continental crust that has been stable for billions of years. The Geological Survey of Western Australia (GSWA), the State's geological agency, divides the craton into large blocks called terranes, and groups of terranes called superterranes [R4]. A terrane and a superterrane meet inside the East Murchison.
The western block is the Youanmi Terrane. The eastern block is the Eastern Goldfields Superterrane, the same block that holds Kalgoorlie further south. GSWA puts the boundary between them at the Ida Fault [R4]. In Samso's reading of the maps, the Black Range District in the west is on one block, and most of the Lawlers and Wiluna districts in the east are on the other.
The gold is in greenstone belts on both blocks. A greenstone belt is a strip of old volcanic and sedimentary rock that has been folded and altered, with granite on either side. In the east, Geoscience Australia names the Agnew-Wiluna belt and the Yandal belt [R5]. Agnew, Bellevue and Wiluna are on the first. Jundee is at the northern end of the second, and Northern Star uses the name Yandal for its Jundee and Thunderbox business. In the west the belts are the Sandstone, Gum Creek and Youanmi greenstone belts, and each project takes the name of its belt [R6] [R7]. Fig 2 shows how narrow the belts are [R8].
Most of the gold is tied to faults and shear zones. A shear zone is a band of rock that has been smeared out, and in places broken, by movement in the crust. Geoscience Australia describes the gold of the Sir Samuel map area, which covers Agnew and Bellevue, as “structurally controlled and associated with brittle-ductile shear zones and quartz veins” [R5]. Geologists call deposits of this kind orogenic gold. Hot fluids carrying gold moved along the breaks and left it there.
Why some of this ore is hard to treat
The geology affects how the ore is processed. Much Western Australian gold ore is free-milling, meaning the gold can be recovered by grinding the ore and dissolving the gold in a cyanide solution. Some ore in the East Murchison is refractory. In refractory ore, part of the gold is locked inside sulphide minerals, which are minerals of metal and sulphur, and cyanide cannot reach it until those minerals are broken down.
Three of the companies in this Insight deal with refractory ore. Wiluna Mining says of Wiluna that gold is “locked within the sulphide crystal lattice” [R9]. Rox's study says that “Up to 25% of the gold in the ore is refractory and locked in solid solution in arsenopyrite”, arsenopyrite being a sulphide of iron and arsenic [R6]. Horizon has 698,000 ounces of gold in sulphide ore at Gum Creek that is outside its feasibility study, because the study covers free-milling ore only [R10].
Refractory ore can be mined at a profit. It needs an extra processing step, and that step costs money to build and to run. Readers should ask of any project in this field whether its ore is free-milling or refractory, and which part of the deposit the study is built on.
3.00 — GOLD MINING HISTORY OF THE EAST MURCHISON
From the 1890s rushes to the open pits of the 1980s and 1990s
Gold was found at Agnew and Wiluna in the 1890s. Youanmi and Gum Creek came later. Gold Fields's history of Agnew records that Patrick Lawlers' prospecting party found gold there in 1894, and that the Waroonga mine opened in 1904 [R11]. The Shire of Wiluna records that the prospectors Woodley, Wotten and Lennon found gold at Wiluna on St Patrick's Day in 1896 [R12]. Rox dates the start of mining at Youanmi to 1908 [R6]. Horizon dates the discovery of gold at Gum Creek to 1926, at a place called Jonesville [R10].
The early mines were underground. The larger tonnages came later. From the 1980s companies went back to most of the old centres, many of them with open pits. The Shire records that mining at Wiluna restarted in 1981 [R12]. Bellevue last operated between 1986 and 1997 [R13]. Gum Creek was mined from the 1980s until 2005 [R10].
Jundee and Thunderbox were new finds of that later period. Exploration at Jundee began in 1978, mining began in late 1995 and the first gold was poured on 27 December 1995 [R14]. Thunderbox was found in 1999 [R15].
No source Samso read gives a production total for the whole field. Fig 3 charts what the owners have published for eight centres. The figures end on different dates, and they leave out the gold produced since, which is large at Jundee, Agnew and Thunderbox. They are company figures and have not been reconciled with State records.
The largest is Agnew and Lawlers. Gold Fields gave the production of those mines from 1894 to 2013, under all their owners, as 7.23 million ounces, from 46.2 million tonnes at 4.9 g/t [R11]. Grade is the amount of gold in each tonne of ore, measured in grams a tonne (g/t). Jundee poured its six millionth ounce in September 2013 [R14]. Wiluna Mining says Wiluna has “Historically produced 4.7Moz Au” [R16].
The three workup projects are smaller. Brightstar gives past production at Sandstone as more than 1.3 million ounces and says there has been no mining there since 2010 [R17]. Horizon says Gum Creek produced “more than one million ounces” [R10]. Rox gives Youanmi's production as 666,995 ounces, from 3.83 million tonnes at 5.4 g/t, mined in several periods between 1908 and 1997 [R6]. Thunderbox had produced 805,000 ounces when processing stopped in September 2007 [R15]. Bellevue produced about 800,000 ounces at about 15 g/t in its last period [R13].
Most of these mines stopped at least once
Youanmi closed in November 1997, and Rox's study gives the reason as “failure to meet production targets and a declining gold price” [R6]. Bellevue closed in the same year [R13]. Gum Creek stopped in 2005 and, in Horizon's words, was “placed on care and maintenance amid lower gold prices” [R10]. Care and maintenance means a mine or plant is shut but kept in working order. Horizon's Annual Report says mining “ceased in 2005 when the gold price was approximately A$560/oz” [R8]. Its documents give more than one account of the closure, and the workup quotes each. Thunderbox stopped in 2007 [R15].
In Samso's reading, these mines closed because the gold price no longer covered the cost of mining at those grades. Gold remained in the ground. Several have since reopened under new owners. Northern Star bought Jundee in 2014 for A$82.5 million [R14]. Saracen Mineral Holdings bought Thunderbox in the same year [R15], and Thunderbox is now a Northern Star mine. Bellevue has treated ore on site since November 2023 [R18]. Samso wrote about the exploration at Bellevue in 2018 [R19].
Youanmi, Gum Creek and Sandstone are the three large centres in the west of the field that have not yet reopened. Each has an ASX company working to change that.
4.00 — WHO PRODUCES GOLD IN THE EAST MURCHISON TODAY
Four owners and five East Murchison gold mines
Four companies produce gold in the field. Samso has not written a workup on any of them. Three are established ASX producers and are noted here from their latest reports. The fourth, Gold Fields, is not ASX-listed. Table 1 at the end of this section lists the mines, and Fig 4 sets their output beside the two study forecasts covered later.
Northern Star Resources, Jundee and Thunderbox
Northern Star Resources reports Jundee, Thunderbox and Bronzewing together as its Yandal production centre. It reports Thunderbox and Bronzewing as one operation, so this Insight counts Bronzewing with Thunderbox. In the year to 30 June 2026 Jundee sold 201,600 ounces and Thunderbox with Bronzewing sold 232,168 ounces, for 433,768 ounces across Yandal [R20]. In the June 2026 quarter Yandal sold 123,937 ounces at an all-in sustaining cost of A$3,228 an ounce [R20].
All-in sustaining cost, or AISC, is the industry's measure of what it costs to produce an ounce at a working mine, including the spending needed to keep the mine going. It leaves out the cost of building the mine, interest and tax, and companies do not all calculate it the same way.
Northern Star's guidance for Yandal in the year to June 2027 is 400,000 to 420,000 ounces at an AISC of A$3,900 to A$4,200 an ounce [R21]. Guidance is a company's forecast. That is fewer ounces than the year just finished, and a higher cost than the June quarter. Thunderbox has a 7 million tonne a year plant, and Yandal's Ore Reserves were 2.6 million ounces within Mineral Resources of 10.7 million ounces at 31 March 2026 [R22]. A Mineral Resource is an estimate of the gold in the ground, and an Ore Reserve is the part of it that a study has shown can be mined at a profit. Section 6.00 has the full definitions.
On 28 September 2026 Northern Star announced that its Board had “received, considered and rejected” a “confidential, opportunistic, unsolicited and conditional non-binding indicative proposal” from Gold Fields [R23]. A non-binding proposal is an offer the bidder is not yet bound to make. The proposal was received on 14 September 2026. It offered 0.3125 new Gold Fields shares plus A$7.25 in cash for each Northern Star share, which the announcement said implied A$27.00 a share at the price of 11 September 2026. The Board rejected it unanimously. Northern Star had made no further announcement on it by the close of 9 October 2026. Gold Fields owns Agnew, so the proposal would have put Agnew, Jundee and Thunderbox under one owner.
Bellevue Gold, Bellevue
Bellevue Gold produced 143,539 ounces in the year to 30 June 2026 at an AISC of A$2,827 an ounce [R24]. Guidance for the year to June 2027 is 150,000 to 170,000 ounces [R24]. The mine is underground and high grade, and its plant treats 1.35 million tonnes a year [R18].
The September 2026 update lowered both the reserve and the resource. Ore Reserves are now 1.0 million ounces at 4.5 g/t, against 1.3 million ounces at 4.7 g/t a year earlier. Mineral Resources are 2.7 million ounces at 8.6 g/t, against 3.1 million ounces at 8.9 g/t [R18]. Mining removes ounces each year, so some fall is expected, and Samso has not separated mining depletion from other changes.
Ramelius Resources, Penny
Penny is a small, high-grade underground mine south of Youanmi. Ramelius Resources trucks its ore to the Mount Magnet mill, which is outside the field, and reports Penny inside its Mt Magnet operation [R25]. In the June 2026 quarter 69,000 tonnes of Penny ore were processed at 8.08 g/t for 17,819 recovered ounces [R25].
Ramelius has given two end dates for Penny. Its June quarterly of 29 July 2026 said “Operationally the Penny mine will extend into the December 2026 Quarter” [R25]. Its outlook of 21 September 2026 listed “Extension of the Penny underground mine to December 2027 (previously June 2026)” [R26]. Both are quoted as published, and the later document is the outlook. The update of 8 October 2026 said wet weather had disrupted haulage from Penny, leaving a stockpile of 27,680 tonnes at 4.78 g/t at the mine [R27].
Gold Fields, Agnew
Agnew is a wholly owned underground mine with a 1.35 million tonne a year plant [R28]. Gold Fields reported production of 230,000 ounces in calendar 2024, down from 245,000 ounces in 2023 [R28]. That is the latest full-year figure Samso read. Agnew is in this Insight because it is one of the largest mines in the field and because its owner made the proposal to Northern Star.
SAMSO TAKE Table 1 tells me the east of this field is already consolidated. Two large companies own three of the four mines in the east, and one of them has just tried to buy the other. The west is different. Its one producing mine sends its ore out of the field, and its three large old centres are in the hands of smaller companies. That is why the three workups are all in the west. When you look at a gold district, do you look first at who is producing, or at who owns the centres that have not yet reopened? |
5.00 — WILUNA MINING AND WESTERN GOLD RESOURCES
Two companies at Wiluna that are not producing gold today
Two more companies have projects at Wiluna. Neither is producing gold today.
Wiluna Mining
Wiluna Mining owns the Wiluna gold operation, the centre that gives the northern district its name. The company is not listed today. Its presentation says it entered administration, where an outside administrator runs a company that cannot pay its debts, in July 2022 and has since exited [R16]. It has lodged a prospectus, the document a company issues to sell shares to the public, to raise A$180 million and list on the ASX, which is called a float [R29]. It describes a resource of 7.1 million ounces in that announcement, and its August presentation gives 91.5 million tonnes at 2.38 g/t for 7 million ounces [R16] [R29]. Both are quoted as published.
The site has a 2.1 million tonne a year leaching plant, which dissolves gold out of ground ore with cyanide, and a 750,000 tonne a year flotation plant, which is the kind of plant that separates sulphide minerals from the rest of the ore [R16].
Until July 2026 the company was producing gold by reprocessing old tailings, the ground waste left after earlier ore was processed. On 25 July 2026 a leach tank ruptured and processing was suspended [R30]. On 24 August 2026 the company said it had decided to suspend all surface and tailings reprocessing operations and to defer processing ore for other companies [R30]. The company lodged a supplementary prospectus, which adds to or corrects the prospectus, on 3 October 2026 [R29]. Samso News has covered the Wiluna Mining float [R31].
Wiluna is therefore a large resource with a plant that is not running, owned by a company that is raising A$180 million through a float. Its presentation describes the resource as 15 per cent free-milling and 85 per cent refractory [R16].
Western Gold Resources
Western Gold Resources (ASX: WGR) owns the Gold Duke project near Wiluna. Its resource is 4.84 million tonnes at 1.8 g/t for about 277,000 ounces [R32]. The company's plan was to mine Gold Duke and have the ore processed at the Wiluna plant under a toll milling agreement, a contract to have ore processed at another owner's plant for a fee.
That plan is on hold for two reasons the company gives in its Annual Report. Heritage consultation “has extended the timetable for commencement of mining”. And Wiluna Mining has “deferred third-party toll milling activities” at the Wiluna plant “until further notice” [R32]. The company says the agreement remains in place and that it is evaluating other processing options. Western Gold Resources is still preparing to mine.
Gold Duke's plan was built on the Wiluna plant, and that plant is shut.
6.00 — THE NEAR-TERM RULE AND THE THREE COMPANIES
A published study and a stated date for first gold
This series gives each workup company a label, and the labels are fixed by the series plan so that every page uses the same words. Near-term producer has a set meaning. A company meets Samso's near-term rule when it has a published feasibility study, either pre-feasibility or definitive, and has stated a date for first gold.
Four terms are needed to read the rest of this Insight. A Mineral Resource is an estimate of the gold in the ground that has reasonable prospects of eventually being mined at a profit. Its confidence levels, from lowest to highest, are Inferred, Indicated and Measured. An Ore Reserve is the part of the Indicated and Measured resource that a study has shown can be mined at a profit, and its levels are Probable and Proved. Inferred material cannot be counted in a reserve. A pre-feasibility study, or PFS, is the middle of three study stages. A definitive feasibility study, or DFS, is the detailed version a lender usually wants.
The label describes how far the paperwork has gone. It says nothing about the quality of a deposit, and it is no forecast that a mine will be built on time. Table 2 sets the three companies side by side.
Table 2 shows three companies with the same label at three different stages. Rox is building. Horizon has finished its study and has to fund it. Brightstar is building a mill in another field and is still drilling and studying at Sandstone. The next three sections take them in that order. Each agrees with its workup, and each workup has more detail than there is room for here.
7.00 — ROX RESOURCES AND YOUANMI
An underground mine under construction, with A$350 million of debt in place
Rox Resources owns 100 per cent of the Youanmi Gold Project, about 480 kilometres north-east of Perth. The study gives the distance as 470 kilometres in some places and 480 in others [R6]. This series classes Rox as “Near-term producer”.
Youanmi meets both parts of the rule. The DFS was published on 13 November 2025 [R6]. The Board approved a final investment decision, its formal commitment to build, on 17 March 2026 [R33]. The company's construction update of 7 September 2026 said the project was “on schedule for gold in mid-CY2027” [R34].
What the study says
The plan is an underground mine and a new plant. The study forecasts an average of 117,000 ounces a year over an initial seven-year mine life, with a peak of 176,000 ounces. AISC is estimated at A$1,978 an ounce and capital before production at A$383 million. Those figures were modelled at a gold price of A$5,200 an ounce [R6]. They are the study's forecasts.
The grade is the highest of the three projects. The Mineral Resource at 30 June 2026 is 12.4 million tonnes at 5.5 g/t for 2,195,000 ounces, of which 1,606,000 ounces are Indicated. The Ore Reserve is 4.8 million tonnes at 4.7 g/t for 727,000 ounces, all Probable. The reserve was estimated using a gold price of A$3,200 an ounce, which is lower than the A$5,200 used for the study's financial forecasts [R35]. In Samso's reading, the reserve counts only ore that pays at the lower price.
Youanmi's ore is partly refractory, as section 2.00 noted. The plant will float the sulphides into a concentrate, the small sulphide-rich part of the ore. The Albion Process then grinds the concentrate very finely and oxidises it in tanks. The gold is leached after that. The study estimates recovery of 90.8 per cent [R6]. Recovery is the share of the gold in the ore that the plant gets out.
Where the build stands
Plate 1 shows the site as published on 7 September 2026. Interquip is building a 1.0 million tonne a year plant under a contract that covers the design, the purchasing and the construction. A 351-room camp is complete [R34]. On 5 October 2026 Rox announced financial close, the point where the loans became available to draw, on A$350 million of debt facilities and a first drawdown of A$90.2 million. The company says Youanmi “remains fully funded to production” [R36]. On 7 October 2026 it said the United North area of the mine was ready for production stoping, which is the mining of the ore itself after the access tunnels are built. The same update said the first two development levels, the tunnels driven along the ore, had extended about 125 metres beyond the study's mine plan, and repeated an aspiration of 150,000 ounces a year [R37]. An aspiration is the company's aim. It is outside the study.
What the workup flags
The Samso Research workup on Rox Resources sets out the risks in detail [R38]. The study's 2025 recovery test work used two composite samples, which are samples blended from drill core, with six variability samples in the flotation tests, and the study does not report a pilot plant, a small-scale trial plant, for the new process [R6]. The lodes, the bands of rock that carry the gold, are narrow, which makes dilution, the waste rock mined along with the ore, harder to control. The study's production target includes 20 per cent Inferred ounces [R6]. Inferred is the lowest confidence level, so a fifth of the planned ounces rest on the least certain part of the resource. And three shareholders hold about 44 to 45 per cent of the company between them. The workup gives holdings that add to 44.4 per cent at 14 September 2026, and the roadshow presentation shows 45.4 per cent [R38] [R33].
Youanmi also closed in 1997 on “failure to meet production targets and a declining gold price” [R6]. The plant of the 1990s floated its sulphide ore and used bacteria to break the sulphides down [R6]. The new plan is at the same mine, with a different oxidation process and a much higher gold price.
8.00 — HORIZON GOLD AND GUM CREEK
A feasibility study, with the funding still to come
Horizon Gold owns the Gum Creek Gold Project, about 640 kilometres north-east of Perth and 90 kilometres north of Sandstone [R10]. This series classes Horizon as “Near-term producer”.
Gum Creek meets both parts of the rule. The DFS was published on 22 July 2026 and gives first gold in the second half of 2028 [R10]. The study says the company will consider a final investment decision alongside project financing and approvals, and targets that decision for Q2 2027, which Samso reads as the June quarter.
What the study says
The plan is a series of open pits feeding a new 2.4 million tonne a year plant at the old Gidgee mill site [R8]. The study forecasts 880,100 ounces recovered over 10 years, an average of 88,000 ounces a year, with 98,000 ounces a year in the first five. AISC is estimated at A$2,995 an ounce and capital before production at A$350.4 million. The study was modelled at a gold price of A$5,500 an ounce, and estimates recovery of 91.5 per cent [R10].
The Ore Reserve is 18.2 million tonnes at 1.24 g/t for 728,400 ounces, all Probable. The reserve was estimated using a gold price of A$4,500 an ounce, which is lower than the A$5,500 used for the study's financial forecasts [R10]. As at Youanmi, the reserve counts only ore that pays at the lower price.
The 880,100 ounces in the study is more than the reserve holds. The study says its production target is 76 per cent Probable Ore Reserve ounces, 18 per cent Indicated ounces and 6 per cent Inferred ounces [R10]. About a quarter of the planned ounces are outside the reserve. The Mineral Resource is 37.97 million tonnes at 1.89 g/t for 2.30 million ounces [R8]. The reserve is about a third of the resource. Part of the difference is the 698,000 ounce sulphide resource, including the Wilsons deposit, which is outside the study. The study says refractory processing options will be evaluated for it [R10].
Gum Creek and Youanmi have reserves of almost the same size, 728,400 and 727,000 ounces. They are different kinds of mine. Youanmi is underground at 4.7 g/t. Gum Creek is open pit at 1.24 g/t and needs a plant more than twice the size to produce fewer ounces a year. Its estimated AISC is about A$1,000 an ounce higher. The two studies are dated November 2025 and July 2026, so their costs are not on the same date. Gum Creek's study has the longer life, 10 years against seven, and it covers free-milling ore only, so it does not need the extra processing step Youanmi does. The comparison is Samso's, from the two studies.
The funding
The study is complete and the money is not yet in place. Horizon had cash of A$24.0 million at 30 June 2026. Its Annual Report of 23 September 2026 carries a going concern note that says “the Group will require additional funding in the next 12 months” [R8]. A going concern note is the directors' statement on whether the company can pay its way for the next year. The auditor drew attention to it under the heading “Material Uncertainty Related to Going Concern”. The same note says the directors are satisfied “there are reasonable grounds to believe that the Group will be able to raise additional funding” [R8].
Zeta Resources held 65.10 per cent of Horizon at 30 June 2026 [R8]. In Samso's reading, a shareholder at that level can support a funding or limit the choices, and what it does can affect the terms for other shareholders.
What the workup flags
The Samso Research workup on Horizon Gold covers these points and others [R39]. It sets out the funding gap, the going concern note and the size of the largest shareholding. It records that the company's documents give more than one account of why Gum Creek closed in 2005, and it quotes each with its source. It also sets the study against the gold price, which section 10.00 of this Insight repeats with today's numbers.
9.00 — BRIGHTSTAR RESOURCES AND SANDSTONE
A large resource with no study yet
Brightstar Resources owns the Sandstone project, about 600 kilometres north-east of Perth [R17]. This series classes Brightstar as “Near-term producer”. The label needs more explanation here than for the other two, because it does not rest on Sandstone.
What the label rests on
Brightstar has two groups of projects. The first is its Goldfields project, which is outside this field. That project has a definitive feasibility study, which the company updated in January 2026 and calls DFS 2.0. A 1.5 million tonne a year plant is under construction at Laverton, and the company says the project is “due to commence gold production in June 2027” [R40]. A published study and a stated first-gold date meet the near-term rule. Both are at Laverton. This Insight does not assess the Laverton build, and its funding and risks are in the workup.
The second group is Sandstone, and Sandstone is at resource stage. Brightstar is drilling there and preparing a pre-feasibility study. The project has a resource and does not yet have a reserve or a published study. The pre-feasibility study is due in the December quarter of 2026. The company's announcement of 5 October 2026 said release was “targeted before the end of 2026” [R41]. The workup records that the study was first targeted for mid-2026 and then for the September quarter [R42]. The company's recent announcements describe the December quarter date as on track [R43].
The company has made aspirational statements about Sandstone, which it says are not production targets. Its presentation of 28 September 2026 gives first production in the second half of 2028 [R44], and its website gives 2029 [R17]. Both are quoted as published. Brightstar is a near-term producer because of Laverton. Its project in the East Murchison is earlier in its life than Youanmi or Gum Creek.
The Sandstone resource
Sandstone is the largest resource of the three. On 28 September 2026 Brightstar reported 79 million tonnes at 1.4 g/t for 3.6 million ounces, of which 30.4 million tonnes at 1.5 g/t for 1.5 million ounces is Indicated. The rest is Inferred. The company's total resource across all projects is 110 million tonnes at 1.5 g/t for 5.2 million ounces [R7]. Fig 5 shows the central part of the project.
The largest deposit area is Two Mile Hill and Shillington, about 10 kilometres south-west of the Sandstone townsite, at 24.6 million tonnes at 1.8 g/t for 1.45 million ounces [R7]. Plate 2 is a photograph of drill core from Two Mile Hill [R44].
Two recent results bear on the study. Laboratory tests of how much gold can be extracted, reported on 24 September 2026, gave average recoveries of 94 per cent across oxide, transitional and fresh ore, which are weathered, part-weathered and unweathered rock. The announcement reports no refractory behaviour in the samples tested. The company said its engineer had provided designs and costings, at pre-feasibility level, for a plant of five million tonnes a year [R43]. On 5 October 2026 the company reported a drill intersection, a length of gold-bearing rock cut by a drill hole, at Bull Oak of 167 metres at 2.07 g/t from 104 metres down the hole [R41]. The 167 metres is measured along the hole and is not the true width of the gold zone. The Bull Oak resource grades 1.0 g/t, so that hole is well above the deposit's average, and one hole does not change a resource.
What the workup flags
The Samso Research workup on Brightstar Resources is in three parts, and the link goes to Part 1 [R42]. It records that Sandstone has a resource and no reserve, and that the Sandstone study was first targeted for mid-2026 and then for the September quarter. It was first released in three parts on 24 September, 29 September and 1 October 2026, and it was updated on 6 October 2026. The update re-dated its share prices and peer table to 5 October 2026, so the link opens the updated version.
SAMSO TAKE I see three versions of the same job in the west of this field. Each company has an old mining centre with more than half a million ounces of past production, and each is trying to bring it back. Rox has the grade and its debt in place, and still has to build the mine and prove the recovery. Horizon has the study and needs the money. Brightstar has the ounces and needs the study. None of them is producing gold in this field today. If you were ranking the three, would you rank them by how many ounces they have, or by how many steps they have left? |
10.00 — THE GOLD PRICE AND INTEREST RATES
Gold is above both study prices and a fifth below its January high
Gold mined in Australia is sold in Australian dollars, so the Australian dollar price is the one that applies to these mines and studies. The prices below are futures prices. A futures contract is an agreement to buy gold at a set price on a later date, and the nearest contract trades close to the spot price, the price for immediate delivery.
The price now
Gold last traded at US$4,218 an ounce at the close of ASX trading on 9 October 2026. That is the price of the most actively traded gold futures contract on the COMEX exchange in New York, and it is the same price the Horizon Gold workup uses. At 69.8 US cents to the Australian dollar, that is about A$6,040 [R45]. The highest close of this cycle was US$5,318 on 29 January 2026, and A$7,581 on 28 January 2026. Gold is 20.7 per cent below that high in US dollars and 20.3 per cent below it in Australian dollars. Fig 6 shows both.
Over a year the gold price has moved differently in the two currencies. A year earlier gold closed at US$3,973, or about A$6,030. The US dollar price is about 6 per cent higher than that, and the Australian dollar price is about level [R45]. The difference comes from the exchange rate. The Australian dollar has risen against the US dollar over the year, and a stronger Australian dollar lowers the local gold price. At today's levels a move of one US cent in the exchange rate changes the Australian dollar gold price by about A$85 an ounce. These comparisons are Samso arithmetic.
What the banks and the World Gold Council say
London Gold Exchange compiles the published gold targets of the large banks. Its list of 1 October 2026 has nine targets for late 2026, from US$4,450 at the low end to a range of US$4,900 to US$5,100 at the high end. One of the nine is Citi's three-month view. All nine are above US$4,218. Most also give a later figure, for 2027 or for the next 6 to 12 months, and those run from US$5,000 to a range of US$5,400 to US$5,600 [R46]. Fig 7 charts them with the date each was issued. A tenth bank on the list gives an average for 2026 and is left off the chart. Samso has read the compilation and has not read the bank notes behind it.
The World Gold Council, the industry's association, reported total gold demand of 1,269 tonnes in the June 2026 quarter, unchanged from a year earlier. Central banks bought 289 tonnes, up 62 per cent. Gold exchange-traded funds, which hold gold on behalf of share market investors, sold 45 tonnes. Jewellery demand fell 17 per cent to 278 tonnes [R47]. In that quarter, stronger central bank buying was set against weaker jewellery and fund demand.
What Samso has published
Samso's current view is in “The Big Consolidation” of 8 July 2026, which followed “The Gold Question” of 21 June 2026 [R48] [R49]. It gave a range of US$3,900 to US$4,500 for the second half of 2026, with a centre of US$4,100 to US$4,300. It gave that base case a weight of about 55 per cent, a higher case about 25 per cent and a lower case, of US$3,200 to US$3,600, about 20 per cent. It also set an objective of US$5,000 to US$5,500 over two years, tied to the US central bank changing course in 2027.
From 8 July to 8 October 2026 there were 66 trading days. Gold closed inside US$3,900 to US$4,500 on 57 of them and above it on 9, all between 19 August and 3 September 2026. It has not closed below US$3,900. Those counts use daily closes. The price of US$4,218 on 9 October is inside the centre of that range. Samso has not published a change to the view. At today's exchange rate the range is about A$5,580 to A$6,440. The count and the conversion are Samso arithmetic.
Interest rates
Both central banks that matter to these companies have raised rates. The US Federal Reserve lifted its target range on 16 September 2026 to 3.75 to 4.00 per cent, its first rise since July 2023, after three cuts late in 2025. Its statement said “Inflation remains elevated” [R50]. The Reserve Bank of Australia has raised its cash rate target, the rate it sets for overnight lending between banks, four times in 2026, from 3.60 per cent to 4.60 per cent. The latest rise was decided on 29 September 2026, and the statement referred to “increasing the cash rate target further if needed” [R51].
Higher rates work against gold through the real yield, which is the interest on a government bond after expected inflation. Gold pays no interest, so a higher real yield raises the cost of holding it. The US 10-year real yield was 1.89 per cent on the day of gold's highest close and 2.87 per cent on 8 October 2026 [R52]. Fig 8 shows gold lower and the real yield higher than in January. The two did not move opposite each other in every month.
What it means for the three companies
The Australian dollar price of about A$6,040 is 16 per cent above the A$5,200 used in the Youanmi study and 10 per cent above the A$5,500 used in the Gum Creek study. Both comparisons are Samso arithmetic. The Youanmi study estimates AISC at A$1,978 an ounce and the Gum Creek study estimates A$2,995 [R6] [R10]. The Gum Creek estimate is closer to the gold price, so its study has less room for a fall in the price. Both are study figures, and AISC leaves out the capital to build.
The bottom of Samso's range, US$3,900, converts to about A$5,580 at today's exchange rate. That is about A$80 above the Gum Creek study price and about A$380 above the Youanmi study price. At today's exchange rate the lower case of US$3,200 to US$3,600 is below both study prices.
Interest rates reach the three companies in different ways. Rox has arranged its debt. Samso has not read whether its interest rate is fixed or moves with the market. Horizon has not arranged its funding. Any debt would be priced at the rates that apply when it is signed. Brightstar has not published a Sandstone study. The gold price in its pre-feasibility study can be set beside the two above when it is released.
11.00 — WHAT TO WATCH
Dates from now to 2028
Table 3 lists the dates the companies have given. Each is the company's statement, and several depend on funding, approvals or other parties.
Two things are not in Table 3 because they have no date. One is whether Gold Fields returns with a new proposal for Northern Star. The other is the restart of the Wiluna plant.
THE RISKS Most of the mines in this field have closed at least once. Youanmi and Bellevue closed in 1997 and Gum Creek in 2005. Gold is more than a fifth below its January high, and both central banks have just raised rates. Northern Star's guidance for Yandal is for fewer ounces at a higher cost. Bellevue's reserve and resource both fell in September. Penny has a stated end date. The three workup projects are not yet mines in this field. Youanmi's 2025 recovery tests used two composite samples, the study reports no pilot plant, and its ore is partly refractory. Gum Creek's project funding is not yet arranged. Horizon's Annual Report carries a going concern note, and one shareholder holds 65 per cent. Sandstone has no reserve or published study yet, and the workup records two earlier target dates for the study. Wiluna has a published resource of about 7 million ounces and a plant that is shut. These points come from the companies' documents and the price data above. |
SAMSO TAKE I read the East Murchison as a field that has always had the gold and has not always had the price. The east is in the hands of large producers. The west is where the smaller companies are, and the next 18 months put a date on each of them. Rox is due to pour first gold in mid-2027. Horizon has targeted its investment decision for the June quarter of 2027. Brightstar's study is due to say what Sandstone costs. Which of those three dates would tell you the most about the field as a whole? |
The vocabulary, in plain EnglishMineral field An area declared by the Western Australian Government for administering mining titles. Craton A piece of continental crust that has been stable for billions of years. Terrane One of the large blocks of crust that make up a craton. Greenstone belt A strip of old volcanic and sedimentary rock, folded and altered, with granite on either side. Most Western Australian gold is in greenstone belts. Shear zone A band of rock smeared out, and in places broken, by movement in the crust. Gold-bearing fluids often moved along shear zones. Orogenic gold Gold deposited from hot fluids along faults and shear zones while the crust was being deformed. Grade, g/t The amount of gold in ore, in grams for each tonne. Free-milling Ore from which gold can be recovered by grinding and cyanide leaching with no treatment beforehand. Refractory Ore in which part of the gold is locked inside sulphide minerals and needs an extra processing step before leaching. Flotation A process that separates sulphide minerals from the rest of the ore to make a concentrate. Recovery The share of the gold in the ore that the plant gets out. Mineral Resource An estimate of the metal in the ground that has reasonable prospects of eventually being mined at a profit. Its confidence levels, lowest to highest, are Inferred, Indicated and Measured. Ore Reserve The part of a resource that a study of at least pre-feasibility level has shown can be mined at a profit. Its confidence levels are Probable and Proved. PFS and DFS Pre-feasibility study and definitive feasibility study. The second and third of the three stages of mine study. Near-term rule Samso's rule for this series. A company is near-term when it has a published PFS or DFS and a stated date for first gold. AISC All-in sustaining cost. What it costs to produce an ounce at a working mine, including the spending needed to keep the mine going. It leaves out the cost of building the mine, interest and tax. Guidance A company's forecast of its production and costs. Workup Samso Research's long study of a single company. Mtpa Million tonnes a year, the usual measure of a mill's capacity. Care and maintenance A mine or plant that is shut but kept in working order. Tailings The ground waste left after ore has been processed. Toll milling Having ore processed at another owner's plant for a fee. Stoping Mining the ore itself underground, after the access tunnels are built. Dilution Waste rock mined along with the ore, which lowers the grade sent to the plant. Final investment decision A board's formal commitment to build a project. Going concern note The statement in a company's accounts on whether it can pay its way for the next year. Futures contract An agreement to buy or sell gold at a set price on a later date. Real yield The interest on a government bond after expected inflation. Cash rate target The rate the Reserve Bank of Australia sets for overnight lending between banks. |
References and sources
Each source below has an identifier, and the same identifier appears in the text where the source is used. Figures 2 and 5 and Plates 1 and 2 are reproduced from company documents, each credited in its caption. Figure 1 and Figures 3, 4, 6, 7 and 8 were drawn by Samso from the data named in their captions. ASX announcements link to the company's announcements page on the ASX website. Government and survey publications carry no link here.
[R1] Department of Mines, Petroleum and Exploration, Western Australia. Mineral Field Boundaries (DMIRS-005) and MINEDEX (DMIRS-001) datasets. Gold sites downloaded 5 October 2026 and boundaries read 11 October 2026. Map compiled by Samso.
[R2] Government Gazette of Western Australia, 5 July 1895, page 934. Proclamation No. 6147 of the East Murchison Goldfield, signed 29 May 1895.
[R3] Government Gazette of Western Australia, 3 June 1904, page 1468. Proclamation of 1 June 1904 dividing the East Murchison Goldfield into the Black Range District and the Lawlers District from 1 July 1904.
[R4] Geological Survey of Western Australia, Record 2010/26. Description of the Youanmi Terrane and the Eastern Goldfields Superterrane, and the Ida Fault between them.
[R5] Geoscience Australia, Record 2002/14. “Geology of the Sir Samuel 1:250 000 sheet area, Western Australia”.
[R6] Rox Resources Limited, 13 November 2025. Youanmi Gold Project Definitive Feasibility Study. ASX announcement. Link
[R7] Brightstar Resources Limited, 28 September 2026. “Two Mile Hill Mineral Resource Doubles to 1.45 Million Ounces”, with the Sandstone and group Mineral Resource update. ASX announcement. Link
[R8] Horizon Gold Limited, 23 September 2026. Annual Report for the year ended 30 June 2026. Link
[R9] Wiluna Mining Corporation, 16 February 2024. Pre-feasibility study, geology and metallurgy sections. Link
[R10] Horizon Gold Limited, 22 July 2026. Gum Creek Gold Project Definitive Feasibility Study. ASX announcement. Link
[R11] Gold Fields Australia, July 2014. Site visit presentation, Agnew/Lawlers Gold Mine, including the history and production of the Lawlers district from 1894 to 2013. Link
[R12] Shire of Wiluna. History of Wiluna, council website, read October 2026. Link
[R13] Bellevue Gold Limited, 2 September 2021. Bellevue Gold Project feasibility study announcement. Link
[R14] Northern Star Resources Limited, May 2014. Jundee fact sheet and the announcement of 13 May 2014 on the purchase of Jundee. Link
[R15] Saracen Mineral Holdings Limited, 7 May 2014. Announcement of the purchase of the Thunderbox operations.
[R16] Wiluna Mining Corporation, August 2026. Company overview presentation. Link
[R17] Brightstar Resources Limited. Sandstone Hub page, company website, read 11 October 2026. Link
[R18] Bellevue Gold Limited, 21 September 2026. Mineral Resource and Ore Reserve update. Link
[R19] Samso Insights, 2018. Bellevue Gold Project, an exploration success. Link
[R20] Northern Star Resources Limited, 29 July 2026. Quarterly Activities Report for the period ended 30 June 2026. Link
[R21] Northern Star Resources Limited, 20 August 2026. Financial results for the year ended 30 June 2026, with guidance for the year to June 2027. Link
[R22] Northern Star Resources Limited, 3 June 2026. Resources, Reserves and Exploration Update at 31 March 2026. Link
[R23] Northern Star Resources Limited, 28 September 2026. Announcement that the Board rejected a non-binding indicative proposal from Gold Fields Limited. Link
[R24] Bellevue Gold Limited, 28 July 2026. Quarterly Activities Report for the June 2026 quarter. Link
[R25] Ramelius Resources Limited, 29 July 2026. “June 2026 Quarterly Activities Report”. ASX announcement. Link
[R26] Ramelius Resources Limited, 21 September 2026. “4-Year Outlook & FY27 Guidance”. ASX announcement. Link
[R27] Ramelius Resources Limited, 8 October 2026. “September 2026 Quarter Update”. ASX announcement. Link
[R28] Gold Fields Limited. Integrated Annual Report 2024, Agnew operating review, company website, read October 2026. Link
[R29] Wiluna Mining Corporation, 11 September 2026. Announcement of its prospectus and A$180 million initial public offering, and the supplementary prospectus notice of 4 October 2026. Link
[R30] Wiluna Mining Corporation, 27 July 2026 and 24 August 2026. Announcements on the tank rupture of 25 July 2026 and the suspension of surface and tailings reprocessing operations. Link
[R31] Samso News. Wiluna Mining and its initial public offering. Link
[R32] Western Gold Resources Limited, 30 September 2026. Annual Report for the year ended 30 June 2026. Link
[R33] Rox Resources Limited, 22 September 2026. Investor roadshow presentation. Link
[R34] Rox Resources Limited, 7 September 2026. “Youanmi Construction and Mining Update”. ASX announcement. Link
[R35] Rox Resources Limited, 9 September 2026. Youanmi Mineral Resource and Ore Reserve statement at 30 June 2026. ASX announcement. Link
[R36] Rox Resources Limited, 5 October 2026. Announcement of financial close on its A$350 million debt facilities. ASX announcement. Link
[R37] Rox Resources Limited, 7 October 2026. United North mining and drilling update. ASX announcement. Link
[R38] Samso Research, 11 October 2026. “Rox Resources (ASX: RXL), Youanmi Gold Project Workup”. Link
[R39] Samso Research, 11 October 2026. Horizon Gold Limited (ASX: HRN), Gum Creek Gold Project workup. Link
[R40] Brightstar Resources Limited, 30 July 2026. Quarterly Activities Report for the June 2026 quarter. Link
[R41] Brightstar Resources Limited, 5 October 2026. Bull Oak drilling results. ASX announcement. Link
[R42] Samso Research. Brightstar Resources Limited (ASX: BTR) workup, in three parts, first released on 24 September, 29 September and 1 October 2026 and updated 6 October 2026. Link
[R43] Brightstar Resources Limited, 24 September 2026. Sandstone metallurgical test work results. ASX announcement. Link
[R44] Brightstar Resources Limited, 28 September 2026. North American conference presentation. Slide 6. Link
[R45] Yahoo Finance. COMEX gold futures, nearest contract (GC=F), and the Australian dollar against the US dollar (AUDUSD=X), daily closes from October 2023, and the last traded price of each at the close of ASX trading on 9 October 2026, as read for the Horizon Gold workup. Australian dollar gold prices, percentage changes and day counts are Samso arithmetic. Link
[R46] London Gold Exchange. Gold price outlook for 2026 and 2027, a compilation of published bank targets, updated 1 October 2026. Read 11 October 2026. Samso has not read the bank notes. Link
[R47] World Gold Council. Gold Demand Trends, Q2 2026, executive summary. Data as of 30 June 2026. Link
[R48] Samso Insights, 8 July 2026. “The Big Consolidation, Where the Gold Price Settles Before Its Next Move”. Link
[R49] Samso Insights, 21 June 2026. “The Gold Question, Which Way for the Gold Price From Here”. Link
[R50] Board of Governors of the Federal Reserve System, 16 September 2026. Federal Open Market Committee statement, and the Open Market Operations page for the history of the target range. Link
[R51] Reserve Bank of Australia, 29 September 2026. Statement by the Monetary Policy Board, and statistical table A2 for the history of the cash rate target. Link
[R52] US Department of the Treasury. Daily par real yield curve rates, 10-year. Link
[R53] Cover photo. Construction at the Youanmi Gold Project, looking south. Rox Resources Limited, “Youanmi Construction and Mining Update”, 7 September 2026, Figure 1. Link
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