Graphite exploration looks for flake graphite in metamorphosed sedimentary rocks, and because graphite conducts electricity, electromagnetic surveys usually find the first targets. Nickel, cobalt, vanadium and zinc each follow different geology. What they share is a supply picture dominated by one or two countries, which is why governments and battery makers want new deposits elsewhere, and why the exploration method has to match the deposit type from day one.

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This guide covers graphite in the most depth, then nickel, cobalt, vanadium and zinc, with the base metal exploration methods that apply to each. Figures come from the US Geological Survey’s Mineral Commodity Summaries 2026 unless stated otherwise; the USGS updates them every February. It is one of our deposit guides, which start from our guide to mining prospecting and deposit types.

“China produced an estimated 82% of the world’s natural graphite in 2025.”

Graphite exploration: where flake graphite deposits form

Natural graphite comes in three commercial forms, and each is a separate exploration problem. The USGS critical-minerals chapter on graphite (Professional Paper 1802-J) describes them:

Flake graphite is the main target for battery anode material, so most graphite exploration concentrates on it. The USGS notes that most flake deposits lie in Precambrian crystalline metamorphic basement, mainly Neoarchean to Proterozoic, and that alumina-rich paragneiss, quartzite and marble near granulite facies make favourable hosts.

What a flake graphite deposit looks like

Deposits usually form stratabound lenses or layers, individually up to tens of metres thick and hundreds of metres long. A typical deposit runs about 8 to 15% carbon, but grades can range from 3% to around 60% locally. The richest zones often sit at contacts between marble and paragneiss or quartzite, in fault zones and fold crests: structural traps you can map from surface. Most flake deposits mined at the time of the USGS study contained at least 8 to 12% graphitic carbon in deposits over 0.5 million tonnes.

Weathering helps. Graphite is stable at surface while other minerals break down, so the USGS notes that weathering can raise grades and make mining easier. Some weathered deposits can be dug with shovels. That makes the saprolite zone above a graphitic schist a shallow, cheap first target for graphite exploration.

Graphite exploration methods, step by step

The USGS describes graphite as the most electrically and thermally conductive of the nonmetallic elements, and in deposits where the flakes touch, that single property organises most graphite exploration programmes. The USGS chapter notes that “a variety of electromagnetic methods” have been used to search for deposits, mainly flake graphite. High-frequency systems suit small shallow targets; lower frequencies reach deeper or define regional targets.

1. Desktop geology. Map Precambrian metamorphic belts, paragneiss and marble units, and structures from government maps and satellite imagery.
2. Airborne EM or conductivity. Fly the belt to find strong linear conductors along favourable units. Our guide to exploration geophysics compares airborne EM with other methods.
3. Ground truthing. Map and sample the conductors. Graphite flakes can turn up in stream sediments, and the USGS notes vanadium, nickel or uranium soil anomalies over some graphite beds.
4. Trenching. Cheap in weathered ground, and it gives bulk samples for flake-size tests.
5. Drilling and metallurgy. Test grade and continuity, then run flotation tests to measure flake size distribution and concentrate purity.

Why flake size matters as much as grade

Two deposits at the same grade can be worth very different amounts. The USGS notes that graphite prices vary with purity, grade and particle size, and battery anode plants need concentrate they can purify and shape into spherical graphite. The USGS reported that Chinese exports of spherical purified graphite rose 29% to 37,400 t in the first nine months of 2025. A graphite exploration company that reports only total graphitic carbon, with no flake-size split, has told you half the story.

Graphite in Tanzania, Mozambique and Madagascar

East Africa is where much of the recent growth outside China has come from. The USGS graphite summary reports that Tanzania more than doubled production to 75,000 tonnes in 2025. Commercial production there began in 2017 in Manyara, a second producer started in Tanga in 2019, and new mines were commissioned in Lindi and Manyara in 2024. In Mozambique, a new mine began production in Niassa and the Balama mine restarted in June 2025. Madagascar produced about 80,000 tonnes.

Much of this output comes from Precambrian metamorphic terrains of the kind the USGS describes as favourable for flake graphite. For graphite exploration in the region, that means mapping marble and paragneiss units, flying EM over them and trenching the weathered zone. Tanzania’s licensing system is covered in our Tanzania mining cadastre and licence guide.

North American graphite exploration

The United States produced no natural graphite in 2025, according to the USGS, while consuming about 71,000 tonnes. Five companies were considering or developing graphite mines in Alabama, Alaska, Montana and New York. One Alaska project completed a feasibility study in 2025 planning about 175,000 tonnes a year of concentrate over 20 years. Canada produced about 8,000 tonnes. That gap between consumption and domestic supply is what drives much of the North American interest in graphite exploration.

What graphite exploration companies should disclose

Graphite exploration results are easy to overstate, because a single strong EM conductor or one rich trench can make a project sound larger than it is. When you read a graphite explorer’s release, look for five things.

• Grade as total graphitic carbon (TGC or Cg), not total carbon, which can include carbonate and organic carbon.
• Flake size distribution from flotation tests, usually reported as the share of concentrate in each mesh class.
• Concentrate purity achieved without and with further purification.
• Drill spacing and true widths, since graphite lenses can pinch and swell along strike.
• Tonnage under a recognised reporting code before any production or offtake claims.

Graphite exploration in weathered ground has one more trap. Grades in the oxidised zone can be higher than in fresh rock below, because weathering removes other minerals. A resource that sits mostly in saprolite may shrink in grade once drilling reaches fresh schist, so check where the drill holes stop.

Graphite exploration in Canada

Canada produced about 8,000 tonnes of natural graphite in 2025, down from 11,700 tonnes in 2024, and the USGS lists Canadian reserves at 5.9 million tonnes. Parts of Quebec and Ontario expose high-grade metamorphic rocks with marble and paragneiss, the combination the USGS flags as favourable. That makes Canada a steady source of graphite exploration projects, even though output is small next to China’s.

Nickel exploration: laterites and sulfides

Nickel exploration splits cleanly in two. The USGS nickel summary estimates that more than 350 million tonnes of nickel sit in identified resources, 54% of them in laterites and 35% in magmatic sulfide deposits.

Laterite nickel

Laterites form when ultramafic rock weathers deeply in tropical climates, concentrating nickel in a soil and saprolite blanket. Exploration is mostly about mapping ultramafic bodies and the weathering profile, then drilling on a close grid to measure thickness and grade. Indonesia’s laterites drove world output to an estimated 3.9 million tonnes in 2025, with Indonesian production up 13%.

Magmatic sulfide nickel

Sulfide deposits form where nickel-rich magma picks up sulfur and the sulfide liquid settles in the base of an intrusion or lava channel. They are dense and conductive, so nickel exploration for sulfides leans heavily on EM and gravity, with downhole EM to find conductors next to or below holes. The same magmatic systems can carry copper, cobalt and platinum-group metals, which is where palladium exploration companies usually look.

Prices have hit nickel explorers hard. The USGS reports that the annual average LME nickel cash price fell an estimated 11% in 2025, the market has been in surplus since 2022, and Australian production fell an estimated 54% as several mines went into care and maintenance. S&P Global’s survey data, reported by BusinessDay, showed nickel exploration budgets falling 37% to US$332 million in 2025. Nickel exploration companies that survive this cycle tend to have high-grade sulfide ground or strong partners.

Nickel exploration companies: what to check

Whether you are partnering with a nickel explorer or assessing your own ground, the questions differ by deposit type.

• For sulfides: is there a mapped ultramafic or mafic host, and do EM conductors sit at its base contact? Were conductors modelled before drilling, and did holes actually intersect them?
• For laterites: how thick is the limonite and saprolite profile, what is the drill spacing, and has anyone tested which processing route suits the ore?
• Byproducts: are cobalt, copper and platinum-group metals assayed, or only nickel?
• Price assumptions: what nickel price does the latest study use, and is it dated before or after the price falls the USGS describes since 2022?

Sulfide explorers usually publish conductor plates, downhole EM results and assay tables. Laterite explorers publish profile thickness and grade by horizon. If neither kind of data is in the disclosures, the project is earlier than its marketing suggests.

Tanzania nickel

Tanzania holds one of the best-known undeveloped nickel sulfide projects. The government issued a Special Mining Licence for the Kabanga nickel project to Tembo Nickel in November 2021. For explorers elsewhere in the region, Kabanga shows that the magmatic sulfide model applies in East Africa too.

Cobalt exploration: following copper and nickel

Almost no one explores for cobalt alone. The USGS cobalt summary says most identified land resources, about 25 million tonnes, sit in three settings: sediment-hosted stratiform copper deposits in Congo (Kinshasa) and Zambia, nickel laterites in Australia, nearby island countries and Cuba, and magmatic nickel-copper sulfides in Australia, Canada, Russia and the United States.

• Congo (Kinshasa) produced an estimated 73% of mined cobalt in 2025, followed by Indonesia at 14%.
• World mine output was about 310,000 tonnes in 2025, with reserves of about 12 million tonnes.
• Export controls: Congo (Kinshasa) banned cobalt exports temporarily from February 2025, then replaced the ban with quotas in October.
• US resources are about 1 million tonnes, mostly in Minnesota.

For cobalt exploration companies, this means the target is really a copper or nickel system with cobalt credits. In the Central African Copperbelt, that is sediment-hosted copper; in Canada and Australia, it is usually nickel sulfide. Cobalt budgets fell 41% to US$31 million in 2025 in S&P’s survey, which shows how rarely it is the primary target.

In practice, cobalt exploration in sediment-hosted copper belts starts with stratigraphy: the ore horizons tend to follow particular reduced sedimentary layers, so mapping and drilling those layers along strike is the core of the work. In nickel terrains, cobalt is simply assayed alongside nickel and copper, and its value is added to the nickel case.

Vanadium, zinc and base metal exploration

Vanadium exploration companies

Vanadium is almost always a coproduct or byproduct. The USGS vanadium summary notes it occurs in phosphate rock, titaniferous magnetite and uraniferous sandstone and siltstone, where it makes up less than 2% of the host rock, and that most of China’s output comes from vanadiferous titanomagnetite processed during steelmaking. China produced about 82,000 of the world’s 110,000 tonnes in 2025. Because titanomagnetite is strongly magnetic, magnetic surveys are the natural first tool. Vanadium redox flow batteries for grid storage are the battery angle, though the USGS notes high capital costs and limited high-purity feedstock remained challenges in 2025.

Zinc exploration

World zinc mine production was about 13 million tonnes in 2025, led by China at 4.1 million, Peru at 1.5 million and Australia at 1.1 million, according to the USGS zinc summary. Zinc exploration targets sediment-hosted deposits, volcanogenic massive sulfides and carbonate-replacement systems. Massive sulfides are conductive, so EM and IP lead, with soil geochemistry for zinc, lead and silver. Zinc exploration companies increasingly also report germanium and gallium, which the USGS notes were being drilled for at the Middle Tennessee zinc mines.

Base metal exploration in one sequence

1. Choose the deposit model (sulfide, laterite, sediment-hosted, VMS).
2. Map host rocks and structures from government data and satellite imagery.
3. Fly magnetics and EM over the favourable units.
4. Follow conductors and magnetic features with soils and ground geophysics.
5. Drill, with downhole EM on sulfide targets.

Comparing battery-metal targets side by side

Here is the whole group on one page. The deposit models differ so much that a licence prospective for one is rarely prospective for another, with the exception of magmatic sulfides, which can carry nickel, copper, cobalt and platinum-group metals together.

Two lessons come out of the table. First, graphite exploration is the odd one out, because it is an industrial-mineral search where flake quality matters as much as tonnage. Second, the metals are dominated by one country each, so deposits elsewhere carry strategic interest that can outlast a weak price cycle. Vanadium illustrates the scale question: the USGS puts world resources above 63 million tonnes, yet because it is mostly a byproduct, those resources say little about how much can be supplied.

How satellite screening fits battery-metal exploration

Satellites help most at the front of each sequence above: mapping host rocks, alteration, structures and weathering profiles over a whole licence before anyone books a survey aircraft. Our satellite-based mineral detection analyses multispectral and hyperspectral data over your boundary to flag mineralised target zones, alteration halos, faults and fractures. Nickel, cobalt, zinc and iron are on our published list of detectable materials. Send us the licence boundary and the commodity you are targeting, and we will say plainly what a satellite screen can and cannot tell you for that ground. For a graphite or vanadium licence, ask us through the mining query form what a structural and host-rock screen can add before you commit to EM.

• Input: coordinates, KML/KMZ or a polygon, plus country and target mineral.
• Output: high-potential zones, prospectivity heatmaps, estimated location and depth ranges, geological interpretation and GIS files.
• Time and cost: 5–20 business days; early-exploration timelines cut from months to days and costs lowered by up to 80–85%.
• Premium+: TargetMax™ drilling-angle recommendations and 3D subsurface models.

We have scanned 100,000+ hectares for 20+ mineral types across 25+ countries. Start by drawing your ground on mining.farmonaut.com (Map Your Mining Site), or see a sample of satellite-driven 3D mineral prospectivity mapping.

Frequently asked questions

Reviewed September 2026 against the USGS Mineral Commodity Summaries 2026 chapters on natural graphite, nickel, cobalt, vanadium and zinc, USGS Professional Paper 1802-J on graphite deposits, S&P Global Market Intelligence’s 2025 budget figures as reported by BusinessDay, and trade press coverage of the Kabanga Special Mining Licence.

Production, price, duty and budget figures are estimates the USGS and S&P revise each year; check the latest editions. Nothing here is investment advice, and we do not recommend any company. Satellite targets are exploration targets, not mineral resources, and need sampling and drilling to confirm.