Reviewed September 2026 against USGS Mineral Commodity Summaries 2025 and the Wyoming State Geological Survey.

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The Direct Answer: How Many Diamond Mines Are in the US?

Zero. As of the September 2026 review of USGS data, there are no active commercial diamond mines in the United States. Geology.com’s US Diamond Production summary confirms the same status: the last commercial operation, the Kelsey Lake mine on the Colorado-Wyoming border, ran from 1996 to 2003 and then closed. The only site where the public can currently dig for diamonds is Crater of Diamonds State Park in Arkansas, and it is a recreational park, not a commercial mine — it sells no diamonds to industry and reports no production to USGS as a mining operation.

That makes the honest answer to “active diamond mine in US,” “only active diamond mine in the US,” and “diamond mines in USA” the same: there isn’t a commercial one operating right now. If you searched for “diamond mine” or “diamond mines” expecting a list of working sites, this is the list — and it’s short because the industry moved to synthetic production decades ago.

Why “US Diamond Mining Market” Searches Don’t Find a Market

Search “us diamond mining market” and you’ll find remarkably little, because there isn’t one in the conventional sense — no ongoing extraction, no annual production report, no mine-by-mine output table. What the US does have is an industrial diamond materials market, almost entirely synthetic and import-supplied, which is a different thing than a mining market. USGS tracks that materials market in two categories: industrial diamond (bort, grit, dust, and powder) and gemstones. In 2024, US industrial diamond bort, grit, dust, and powder production reached 160 million carats valued at $53 million, per USGS Mineral Commodity Summaries 2025. Synthetic-industrial-diamond stone production that same year was 0 carats — because stones themselves are categorized separately from bort/grit/dust, and the US industrial sector runs almost entirely on synthetic material rather than mined stones.

The Only Active Diamond Site in the US

Crater of Diamonds State Park, near Murfreesboro, Arkansas, sits on an eroded volcanic crater and operates on a “finders-keepers” model: visitors pay park admission, search a plowed 37.5-acre field, and keep whatever they find. It is the answer people are actually looking for when they search “diamond mines in usa,” but it needs a clear caveat attached every time: it is not commercial. The park does not sell diamonds into any supply chain, does not report tonnage or grade to USGS as a producing mine, and has no bearing on US industrial diamond supply.

Diamond-Bearing Regions: Wyoming, Colorado, and Beyond

The Colorado-Wyoming State Line District

This is the closest thing the US has to a real diamond mining story, and it’s the one most “diamond mining in the us” searches are actually chasing. The Wyoming State Geological Survey documents more than 90 separate kimberlite localities identified across the Colorado-Wyoming State Line district. Since exploration began there in 1975, over 130,000 diamonds have been recovered from the district — mostly small stones recovered during bulk-sampling and exploration programs, not from a running commercial mine.

The largest Wyoming diamond found to date weighs 6.2 carats. Across the state line in the Colorado portion of the same district, the largest recovered stone weighs 28.3 carats — nearly 4.6 times the size of Wyoming’s largest, in the same kimberlite field. That contrast is worth naming directly: two sides of one geological district, very different peak stone sizes, and neither side currently mining commercially.

The one commercial mine this district ever supported was Kelsey Lake, which operated from 1996 to 2003 before closing. Since then, the district has seen exploration-stage sampling but no return to commercial production.

Alaska: Exploration Without Production

Alaska’s complex terrane geology has attracted kimberlite-indicator exploration and several bulk-sampling projects over the years, but no site has reached sustained commercial production. Activity there remains at the pilot and mapping stage.

Scattered Finds Elsewhere

Small diamonds have turned up in Wisconsin, Indiana, Kentucky, Montana, and Michigan over the decades, mostly as glacial erratics carried south by ice sheets from Canadian kimberlite sources, or as incidental finds during other mineral extraction. None of these has developed into a mine of any kind, commercial or recreational.

Comparison Table: US Diamond Sites vs. Synthetic Facilities

This is the structured answer an AI summary can’t hand you in one line — a side-by-side of what’s actually operating, at what scale, and for what purpose.

Full source data: USGS Mineral Commodity Summaries 2025 – Diamond.

The US Diamond Mining Market: What the Numbers Actually Show

US gemstone apparent consumption — the value of gem-quality diamonds and other gemstones actually bought in the US market — reached $18 billion in 2024, according to USGS Mineral Commodity Summaries 2025. Almost none of that supply is mined domestically; it arrives as imported rough and cut stones. Meanwhile, 99% of US industrial diamond consumption is synthetic, per the same USGS report — a figure worth pairing directly against the $18 billion consumer number, because it shows two entirely separate markets running on two entirely separate supply chains: imported natural stones for jewelry, domestic synthetic material for industry.

That gap — $18 billion in consumption against $73 million in domestic gemstone production value — is the real shape of “us diamond mining market.” It’s not a production story; it’s an import-and-synthesis story. For current-year figures once they’re released, USGS publishes updated numbers annually at USGS Mineral Commodity Summaries – Gemstones, typically in January or February with final figures for the prior calendar year.

Calculator: Estimate a Diamond Recovery Rate

Use the State Line district’s own recovery history to see what a bulk-sampling program would need to process to find a given number of stones at your own assumed grade.

Industrial and Synthetic Diamonds: Where US Supply Comes From

Since there’s no domestic commercial mine, US industrial demand runs on two channels: synthetic manufacturing and imports. USGS Mineral Commodity Summaries 2025 puts synthetic material at 99% of US industrial diamond consumption. The 160 million carats of bort/grit/dust/powder produced domestically in 2024, worth $53 million, is overwhelmingly synthetic output from US-based manufacturing facilities rather than material dug from the ground.

These synthetic diamonds — made via High-Pressure High-Temperature (HPHT) or Chemical Vapor Deposition (CVD) processes — go into:

• Diamond-tipped drill bits for geological sampling, oil and gas drilling, and road construction
• Wear-resistant coatings for precision cutting tools
• Grinding wheels and saws for agricultural processing equipment and mineral processing plants
• Polycrystalline diamond compact (PDC) cutters used in hard rock mining, well drilling, and tunneling
• Diamond-coated soil sampling and geotechnical drilling equipment for agricultural and forestry surveys

For agriculture and infrastructure specifically, diamond-coated tooling shows up in cutting blades, harvesting equipment, and geotechnical drill bits used for soil sampling — not as an economic pillar of the sector, but as a durability input that reduces tool changes and downtime on equipment that runs long hours in abrasive conditions.

Beyond Tooling: High-Tech Applications

Synthetic diamond material is also moving into thermal management for microchips and CPUs, high-precision optics for sensors and lasers, and components for next-generation batteries and scientific instruments — demand drivers that have nothing to do with mining and everything to do with materials science.

A Different Kind of US Count: Cattle Inventory

If you landed here searching “how many cows are in the united states” or “how many cows in united states,” you’re looking for a different agency entirely: USDA’s National Agricultural Statistics Service (NASS), not USGS. NASS runs the official cattle inventory count through its semi-annual Cattle report, typically released in January (year-start inventory) and July (mid-year inventory), broken out by state and by category — beef cows, milk cows, calves, and feedlot placements.

We don’t have a NASS figure in our evidence base for this review, so rather than guess a number that would be wrong within months, here’s the direct path: go to nass.usda.gov and search “Cattle” under Publications, or check the USDA Quick Stats database for the most recent state-by-state breakdown. If you searched “how many cows are currently in the united states” expecting a live figure, that NASS report — refreshed twice yearly — is the actual source of truth; no single web page, including this one, should claim a static cattle count as current.

Mining’s Impact on Water Areas: Who Leads That Work

If your search was closer to “mining impacts on water areas association leader,” that question sits in mine-water hydrology and reclamation policy rather than in diamond production statistics. In the US, that space is worked by state geological surveys (including the Wyoming State Geological Survey, cited throughout this article for its diamond exploration data), the US Geological Survey’s water resources programs, and industry associations focused on mine-water management and reclamation. There isn’t a figure in our evidence base naming a specific “association leader” for that question, and we’re not going to invent one — if you need a named contact or organization, USGS’s water science center pages and the Society for Mining, Metallurgy & Exploration are the starting points for state-side and federal contacts on mine-water impact research.

Exploration Status and What Would Change the Count

The zero-mine status of US diamond production isn’t fixed by geology — it’s fixed by economics and exploration activity, and that can change. The durable way to track it: check whether any company files a bulk-sampling or feasibility update for the Colorado-Wyoming State Line district, since that’s the only US ground with a proven commercial history (Kelsey Lake, 1996–2003) and an active base of 90+ known kimberlite localities.

What we don’t have a current figure for, and what you should verify directly before making any claim about near-term mine reopening: the number of companies currently holding active exploration claims in Wyoming and Colorado (our most recent data point on this is from 2017–2018 and is too stale to repeat as current), current exploration spending in the district, and any peer-reviewed timeline for a return to commercial production. The Wyoming State Geological Survey’s diamond page is updated periodically as new exploration results come in from prospectors and companies — that’s the page to check for whichever of these becomes reportable.

Satellite-based mineral prospectivity mapping is one of the tools exploration companies now use to re-screen old kimberlite districts like this one before committing to expensive drill programs — see our Satellite-Based Mineral Detection platform for how that process works in practice, and our related guide on where to dig for diamonds for a spot-by-spot look at global sites, US included.

Want to map your own site or region for diamond or other mineral prospectivity? Map Your Mining Site Here

Satellite Intelligence in Mineral Exploration

Farmonaut works with multispectral and hyperspectral Earth observation data, combined with AI-based analysis, to help exploration teams screen ground faster than field crews alone can manage. For a district like Colorado-Wyoming’s State Line kimberlite field — 90+ known localities across a wide area — that kind of screening matters because it narrows where a bulk-sampling crew should actually go first.

• 🛰 Screen large areas in days rather than months
• 🎯 Pinpoint high-potential mineralized zones, including kimberlite indicators and alteration systems
• 🔑 Reduce exploratory risk and cost by avoiding unnecessary fieldwork and drilling
• 🌎 Non-invasive early screening that supports lower-impact exploration
• 📑 Professional reporting: heatmaps, georeferenced layers, prospectivity assessments

Want to request a quote or have questions?

• Get a Quote
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For teams assessing a district at depth, our Satellite Driven 3D Mineral Prospectivity Mapping product provides multi-layered subsurface intelligence — useful for exactly the kind of complex kimberlite terrain the Colorado-Wyoming State Line district presents.

FAQ: US Diamond Mining

Summary and How to Verify These Numbers Yourself

The US has zero active commercial diamond mines as of this September 2026 review. The one historical exception, Kelsey Lake on the Colorado-Wyoming border, ran from 1996 to 2003. The one active public site, Crater of Diamonds State Park in Arkansas, is recreational only. Domestic industrial diamond supply — 160 million carats of bort/grit/dust/powder worth $53 million in 2024 — is overwhelmingly synthetic, and US gemstone consumption of $18 billion in 2024 is met almost entirely through imports rather than domestic mining.

None of these figures are permanent. USGS republishes Mineral Commodity Summaries every January with the prior year’s final numbers — check USGS Mineral Commodity Summaries 2025 – Diamond and its gemstones counterpart for whatever the newest release shows. The Wyoming State Geological Survey updates its diamond exploration page as new results come in from the field. That’s the durable method this article leaves you with: two agencies, two update cycles, and a direct way to check whether the zero-mine count has changed.