Vermiculite: Extraction
How altered mica becomes a mineral that swells
What this tab covers How it is mined, drilled or grown, and processed into a tradeable form: the main methods compared, their unit economics, by-products, and the companies that do this work globally and in India.Vermiculite is a hydrated, mica-like silicate formed by alteration of biotite or phlogopite, often in igneous complexes such as Palabora in South Africa. It is mined in open pits and concentrated by screening and air separation. The concentrate goes to exfoliating plants, where rapid heating turns water between the layers to steam. The flakes expand into light, porous, worm-like granules. US concentrate is mined in South Carolina and Virginia, then exfoliated at 12 plants in seven states.
Vermiculite is mined in only about a dozen countries, and South Africa, the US and Brazil supply about two thirds of the total. The ore is mined in open pits and turned into a crude concentrate sorted by flake size. The concentrate is the traded product. Because exfoliated vermiculite is so light and bulky, expansion is done in furnaces close to customers rather than at the mine. Quality depends on flake size, purity and freedom from fibrous contaminants, which matters since the closed Libby, Montana mine left a legacy of asbestos contamination.
Methods compared
| Method | Share of supply | Typical scale | Recovery / efficiency | By-products | Unit cost |
|---|---|---|---|---|---|
| Open-pit mining and dry concentration (carbonatite deposits, South Africa) | South Africa about 35% of world output (160,000 t of 460,000 t, 2025, USGS) | Palabora produced 155,000 t in 2019 (MiningDataOnline) | n/a | Mined alongside copper and magnetite at the Palabora complex | not published; South African exports under HS 253010 averaged about $298/t in 2024 (indicative, basis: UN Comtrade value/weight) |
| Open-pit mining in the US (South Carolina and Virginia) | about 22% of world output (100,000 t, 2025, USGS) | about 100,000 t of concentrate a year from two companies combined | n/a | n/a | not published (USGS lists ex-plant price as not available, 2021-2025) |
| Exfoliation (furnace expansion of concentrate) | nearly all concentrate is exfoliated before use (USGS) | 12 US plants run by 10 companies; 55,000 t of exfoliated product in 2025 | n/a | n/a | not published |
How each method works
Open-pit mining and dry concentration (carbonatite deposits, South Africa)At Phalaborwa in Limpopo, vermiculite is mined from an open pit within the same igneous complex that hosts the Palabora copper and magnetite operations. Ore is crushed and classified into size grades of crude concentrate for export.
Large, long-lived deposit with 14 Mt of reserves; single dominant supplier for export markets.
USGS MCS 2026; MiningDataOnline Palabora profile; Palabora product page; UN Comtrade 2024 Open-pit mining in the US (South Carolina and Virginia)Two companies mine and process vermiculite in South Carolina and Virginia and ship concentrate to exfoliators. Output is rounded by USGS to protect company data.
Close to the main US market; US reserves of 25 Mt are the largest listed.
USGS MCS 2026, Vermiculite Exfoliation (furnace expansion of concentrate)Crude concentrate is fed through a furnace and heated quickly. Interlayer water flashes to steam and the flakes expand into light accordion-like granules, which are then graded and bagged.
Located near users to avoid shipping bulky product; needs fuel for heating.
USGS MCS 2026, Vermiculite Unit economics are indicative ranges from the sources named; costs vary widely by deposit, region and year.By-product supply
At Phalaborwa in South Africa, vermiculite comes from the same igneous complex as copper and magnetite (MiningDataOnline), but it is mined for its own value rather than recovered as a by-product.
Who does it: global
| Company | Country | Activity | Volume | Year | Source |
|---|---|---|---|---|---|
| Palabora Mining Company Later years are behind a paywall; South Africa produced about 160 kt in 2025 (USGS). | South Africa | mining (vermiculite, also copper and magnetite); owned 59.2% by HBIS Resources | 155 kt vermiculite | 2019 | MiningDataOnline, Palabora Operation profile |
| Two US producers (South Carolina and Virginia) USGS does not name the companies and rounds output to protect company data. | US | mining and concentration | 100 kt concentrate (combined, rounded) | 2025 | USGS Mineral Commodity Summaries 2026, Vermiculite |
Who does it: India
India mined about 2,000 t in 2025 and has 1.6 Mt of reserves (USGS); no producer volumes were found. India imported 80,000 t under HS 253010 (vermiculite, perlite and chlorites) worth $11.6 million in 2024, 5.0% of world import value (UN Comtrade).