Junior explorers often have one thing in common: identifying a mineral deposit that could eventually support a mine.
Exploration sits at the very beginning of the mining project lifecycle, with the higher risk activities often returning a limited reward.
Following the exploration and discovery stage, mining companies can then progress through resource definition, economic assessment and development studies, mine construction, and production. They then move through to rehabilitation and closure after the mine’s lifecycle has been completed.
A mineral resource estimate (MRE) provides a foundation for determining a mineral deposit’s geological certainty and economic potential. It also marks an important milestone for junior explorers.
A resource estimate describes the quantity and grade of mineralisation that has reasonable prospects for eventual economic extraction, as reported by Mining.com.au.
But joining the million-ounce club can look different for various gold-focused junior explorers.
Joining the million-ounce club
Prodigy Gold (ASX:PRX) is a great example of a junior explorer hosting over a million ounces in resources, spread across numerous deposits in the Northern Territory.
The company’s total resources equate to 23.8 million tonnes (Mt) @ 1.4 grams per tonne gold (Au) for 1.049 million ounces (Moz). This resource accounts for 9.5Mt @ 1.4g/t Au for 423,000 ounces indicated and 14.4Mt @ 1.4g/t Au for 626,000 ounces inferred across the Tanami North and Tanami West project areas.
The Tanami North Project spans 2,415km2 across six granted exploration licences, five exploration application titles, and one mineral lease application.
Prodigy has two current MREs at Tanami North, covering the Tregony and Hyperion deposits with a total inventory of 11.7Mt @ 1.4g/t Au for 515,000 ounces.
Meanwhile, the Tanami West Project covers a similar land mass, including 16 granted exploration titles, two exploration application titles, and two granted mineral leases for a total area of 2,248km2.
Tanami West also comprises two MREs, covering the Buccaneer and Old Pirate deposits. The project has a total inventory of 9.96Mt @ 1.5g/t Au for 474,000 ounces.
Providing multiple resource estimates over each project area is deemed a crucial way to reduce geological uncertainty. This also allows Prodigy Gold to test different geostatistical scenarios and derisk financial and operational decisions moving forward.
Relying on a singular MRE for the mining model can lead to either over-optimistic or over-pessimistic planning. In contrast, multiple avenues provide a company with a more balanced understanding of the project area and its geological structure.
But a first MRE is only the beginning for most explorers.
A million and counting
The exploration stage of a project is rarely short, often taking anywhere from a couple of years to a decade.
Even completing exploration work in this timeframe is sometimes unachievable, as it depends on the location, geology, cultural heritage, politics of the area, and how easily the land is accessible, as mining major Rio Tinto (ASX:RIO) reports.
By continuing to update resource estimates over this timeframe, explorers are able to reflect on new data, correct early uncertainties, and guide better business choices.
Sometimes these resource updates will more than pay off for the company. Sinclair Gold (ASX:SGC) understands this.
Earlier this month, Sinclair Gold doubled the existing resource estimate for the Mt Henry Gold Project in Western Australia — pushing the company into the million-ounce club.
The company added an additional 900,000 ounces of contained gold to the existing 900,000 ounces that came with the project when it was acquired in February 2026.
Mt Henry now contains an MRE of 48Mt @ 1.2g/t Au for 1.8Moz across the Mt Henry, Selene, and North Scotia deposits.
Not long after reporting the MRE update, Sinclair Gold extended mineralisation beyond the resource boundary through step-out drilling, with ‘strong’ assays indicating there is room for further resource growth.
The company intends to release another updated MRE before the end of the 2027 financial year, with five drill rigs continuing to operate on the project in 2026.
Making the ounces add up
Just because the exploration stage is hard, it doesn’t make everything smooth sailing following an MRE.
Moving into the development stage requires a company to convert this geological discovery into an economically viable, permitted, and financed mining operation through numerous technical studies and infrastructure planning.
PC Gold (ASX:PC2) has reached this point and is ready to meet the development needs of its Spring Hill Gold Project.
Located in the NT’s Pine Creek region, Spring Hill hosts a resource estimate of 1.51Moz @ 1.1g/t Au, including over 1Moz in the indicated category.
The company recently appointed two non-executive directors to strengthen the board’s development capability for Spring Hill.
With Richard Clark and Matthew Scully joining the team, Executive Chairman Ashley Pattison previously said their appointments mark a ‘deliberate’ step in PC Gold’s evolution from explorer to mine developer.
“As we advance the Prefeasibility Study for Spring Hill, we wanted directors who have actually financed, built, and commissioned mines and processing plants — and few people anywhere have done that as successfully as [Rick and Matt],” Pattison says.
From ounces to a mine
Beyond exploration, the final investment decision (FID) marks one of the final stages before production.
It’s a critical turning point in the development stage that determines whether a company will progress to mine construction.
Aurum Resources (ASX:AUE) is nearing the production stage, with a FID targeted for the Boundiali Gold Project in Côte d’Ivoire in late Q4 2026.
The company is currently progressing a Definitive Feasibility Study for Boundiali, which has a resource estimate of 3.22Moz @ 1.0g/t Au.
Boundiali is set to begin gold production in H1 2028 with a life-of-mine production of approximately 1.5Moz Au over 11 years.
Aurum is focused on discovering and developing gold mines in Côte d’Ivoire, with the Boundiali and Napié projects providing a total resource inventory of 4.38Moz gold.
Recently, the company extended gold mineralisation outside of the resource estimate at the BST1 deposit in an ongoing 150,000m diamond drilling campaign at Boundiali.
Aurum Resources intends to update Boundiali’s MRE early in the next quarter, with a drilling cut-off at the end of this month.
Write to Maddison Elliott at Mining.com.au
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