Vermiculite
Vermiculite is a layered magnesium aluminium silicate mineral that holds water between its sheets. Heated quickly, that water turns to steam and forces the layers apart, and the flake concertinas open into a light, worm shaped granule many times its original volume. The concentrate is mined and screened into size grades at origin and exfoliated close to the point of use, because expanded vermiculite is mostly air. It is used as a horticultural growing medium and seed raising substrate, as a carrier for fertiliser and agricultural chemicals, as loose fill and board insulation, in fireproofing sprays, refractory linings and fire rated board, in brake linings and gaskets, as a lightweight aggregate in plaster and concrete, and as packaging for hazardous goods.
Listed vermiculite markets
Each line is a grade at a delivery point. Open one for its full specification and terms.
Grades
A vermiculite contract turns on the size grade of the concentrate and on how far it exfoliates, because the flake size sets the application and the expansion sets the value of the tonne.
Particle size and sizing
5 grades
| Grade | Definition |
|---|---|
| Size grade of the concentratePercentage by mass retained at each stated aperture, with the grade named | Determined on test sieves conforming to ISO 3310. The size grade ladder runs from large flake down to micron grade, and it is the primary commercial term because each band goes to a different application. |
| Top sizeMillimetres, maximum | Set by the screen deck at the plant, and a rejection term because oversize will not pass a furnace feeder. |
| Fines below the stated aperturePercentage by mass, maximum | Fines do not exfoliate usefully and they dust in the plant. |
| Grading of the exfoliated productPercentage by mass retained at each stated aperture | The size ladder of the expanded granule, which is coarser than the concentrate it came from. |
| Median particle size of micron gradesMicrometres | Determined by laser diffraction under ISO 13320 for the fine and milled grades. |
Physical properties
15 grades
| Grade | Definition |
|---|---|
| Material stateDeclared, as concentrate or exfoliated | Concentrate is sold by weight and exfoliated product effectively by volume. They are different trades. |
| Exfoliation ratioReported as the ratio of expanded volume to unexpanded volume, at the stated furnace conditions | Determined in a laboratory exfoliation furnace under the method named in the contract. It is the commercial measure of what the concentrate is worth. |
| Loose bulk density of the exfoliated productKilograms per cubic metre | The defining grade term for expanded vermiculite. Every application is written to a density band. |
| Bulk density of the concentrateKilograms per cubic metre | Loose and tapped, setting the hold, the bag and the freight cube. |
| Free moisturePercentage by mass, maximum | Determined by oven drying. It is fuel cost in the exfoliator and a caking problem in the bag. |
| Interlayer water and loss on ignitionPercentage by mass | Determined at the stated temperature. The water between the layers is what drives the exfoliation. |
| Exfoliation temperatureDegrees Celsius | The furnace window in which the flake opens properly, which the exfoliator sets its plant to. |
| Thermal conductivityWatts per metre kelvin, at the stated mean temperature | Measured on the exfoliated product. The performance term for insulation and fire protection grades. |
| Refractoriness and shrinkage on reheatingDegrees Celsius, and percentage linear change | For refractory and fire protection grades, whether the granule holds its volume at service temperature. |
| Cation exchange capacityMilliequivalents per hundred grams | Determined by the named method. It is the property behind fertiliser and chemical carrier use. |
| Water holding capacity and air filled porosityPercentage by volume | The horticultural grade terms, deciding how a substrate drains and breathes. |
| Crush resistance of the exfoliated granuleKilopascals, or percentage volume loss under the stated load | Whether the granule survives being mixed into a plaster, a board or a substrate. |
| ColourDeclared, and reported in the CIE colour space where specified | Golden, silver and dark grades from different deposits, relevant to horticultural and decorative use. |
| pH of a water extractpH units | Determined on a slurry at the stated solids. Vermiculite is mildly alkaline and it matters in a growing medium. |
| Soluble salts and conductivityMilligrams per kilogram, and microsiemens per centimetre | Determined on a water extract. A horticultural grade term. |
Chemical assay
7 grades
| Grade | Definition |
|---|---|
| SilicaPercentage by mass | Determined by X-ray fluorescence under ISO 12677. |
| Magnesium as magnesium oxidePercentage by mass | A defining oxide of the vermiculite structure. |
| AluminaPercentage by mass | The second major oxide of the layer structure. |
| Iron as ferric and ferrous oxidePercentage by mass | It sets the colour and it affects the exfoliation behaviour. |
| Potassium as potassium oxidePercentage by mass | Tracks the residual mica interlayered with the vermiculite, which does not exfoliate. |
| Calcium as calcium oxidePercentage by mass | Carbonate and gangue reporting with the concentrate. |
| Hydrobiotite and mica contentPercentage by mass | The interstratified and unaltered fraction, which limits how far the concentrate will open. |
Contaminants and regulated substances
7 grades
| Grade | Definition |
|---|---|
| Asbestiform amphibole fibresPass or fail, against the named analytical method | The governing acceptance term in this trade. Every lot is certified free of amphibole fibre by the method and the laboratory named in the contract, and no cargo moves without it. |
| Respirable fibre countFibres per cubic centimetre, against the named method | The workplace measure supporting the fibre certification. |
| Crystalline silicaPercentage by mass | Declared on the safety data sheet, driving the dust controls. |
| Heavy metalsMilligrams per kilogram, maximum | Arsenic, lead, cadmium and mercury against the limit at the destination for the intended use. |
| RadionuclidesBecquerels per kilogram | Screened where the deposit or the destination requires it. |
| Horticultural substrate complianceDeclared | Where the vermiculite is placed on the market as a growing medium, the applicable substrate or fertiliser regulation at the destination. |
| Construction and fire protection conformityDeclared | The conformity route, fire classification and marking required at the destination, named on the contract. |
Delivery, documentation and certification
10 grades
| Grade | Definition |
|---|---|
| Form and packingDeclared | Bulk, big bags of a stated net weight, paper or polywoven bags palletised and shrink wrapped, or containerised bulk in liners. The pack is a price term because it drives the handling cost at both ends. |
| Moisture at loadingPercentage by mass, maximum | Determined by oven drying on a loading sample. Moisture is paid for as mineral unless the contract sets a dry weight basis, so it is always specified. |
| Weight basisDeclared | Wet or dry metric tonnes, on shipped weight or landed weight, with the survey house named and the draft survey or weighbridge method stated. |
| Sampling and assay protocolDeclared | Who samples, at which point, to what standard, how the sample is split and sealed, and which laboratory umpires a dispute. It is agreed before loading, not after. |
| Transportable moisture limitPercentage by mass | Where the cargo is a group A material under the maritime bulk cargoes code, the flow moisture point and the transportable moisture limit are certified before loading. |
| Safety data sheetDocument, to the globally harmonised system format | Classification, handling and respirable crystalline silica statement, supplied with every consignment. |
| Certificate of analysisDocument, per lot | Issued by the named laboratory against the contract specification, referencing the lot and the sampling record. |
| Regulatory registrationDeclared | Chemical registration at the destination where the mineral requires one, named on the contract. |
| Origin and due diligenceDeclared, with the mine or plant named | Country of origin, the mine or processing plant, and where required the responsible sourcing statement. |
| Fibre certificateDocument, per lot | The amphibole fibre analysis from the named laboratory, issued against every lot and travelling with the cargo. |
Grades outside this list trade on request. Send us the contract specification you work to and we will price against it.
Locations
| Country | Region | We trade it as |
|---|---|---|
| South Africa | Southern Africa | Origin and destination |
| China | East Asia | Origin and destination |
| Brazil | South America | Origin and destination |
| United States | North America | Origin and destination |
| Zimbabwe | Southern Africa | Origin and destination |
| Uganda | East Africa | Origin and destination |
| Kenya | East Africa | Origin and destination |
| Tanzania, United Republic of | East Africa | Origin and destination |
| Russian Federation | Eurasia | Origin and destination |
| India | South Asia | Origin and destination |
| Turkiye | Europe and Anatolia | Origin and destination |
| Spain | Southern Europe | Origin and destination |
| Portugal | Southern Europe | Origin and destination |
| United Kingdom | Northern Europe | Origin and destination |
| Germany | Western Europe | Destination |
| France | Western Europe | Origin and destination |
| Italy | Southern Europe | Origin and destination |
| Netherlands | Northwest Europe | Destination and trading hub |
| Belgium | Northwest Europe | Destination |
| Poland | Central Europe | Origin and destination |
| Czechia | Central Europe | Origin and destination |
| Bulgaria | Southeast Europe | Origin and destination |
| Romania | Southeast Europe | Origin and destination |
| Ukraine | Eastern Europe | Origin and destination |
| Kazakhstan | Central Asia | Origin and destination |
| Greece | Southern Europe | Origin and destination |
| Israel | Middle East | Origin and destination |
| Egypt | North Africa | Origin and destination |
| Morocco | North Africa | Origin and destination |
| Algeria | North Africa | Origin and destination |
| Tunisia | North Africa | Origin and destination |
| Nigeria | West Africa | Origin and destination |
| Ghana | West Africa | Origin and destination |
| Senegal | West Africa | Origin and destination |
| Mozambique | Southern Africa | Origin and destination |
| Madagascar | Southern Africa | Origin and destination |
| Namibia | Southern Africa | Origin and destination |
| Mexico | North America | Origin and destination |
| Canada | North America | Origin and destination |
| Argentina | South America | Origin and destination |
| Chile | South America | Origin and destination |
| Peru | South America | Origin and destination |
| Colombia | South America | Origin and destination |
| Bolivia, Plurinational State of | South America | Origin and destination |
| Australia | Oceania | Origin and destination |
| New Zealand | Oceania | Origin and destination |
| Japan | East Asia | Destination |
| Korea, Republic of | East Asia | Destination |
| Thailand | Southeast Asia | Origin and destination |
| Viet Nam | Southeast Asia | Origin and destination |
| Indonesia | Southeast Asia | Origin and destination |
| Malaysia | Southeast Asia | Origin and destination |
| Pakistan | South Asia | Origin and destination |
| Sri Lanka | South Asia | Origin and destination |
| Singapore | Southeast Asia | Trading and finance |
| Switzerland | Western Europe | Trading and finance |
| United Arab Emirates | Middle East | Destination and trading hub |
| Saudi Arabia | Middle East | Origin and destination |
| Qatar | Middle East | Origin and destination |
| Oman | Middle East | Origin and destination |
| Iran | Middle East | Origin and destination |
Origins and destinations outside this list trade on request. We are not limited to the locations shown here.
Timing
Production is when the mineral is mined and processed at origin, which follows the mine plan and the weather at the pit rather than a crop season. Arrival is when a shipment from that origin typically lands in a consuming market. The gap between them is drying, grading, bagging and the voyage.
HarvestArrival
| Origin | J | F | M | A | M | J | J | A | S | O | N | D | Window |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| South Africa | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest Jan to Dec, arrival Jan to DecThe Palabora deposit in Limpopo is the benchmark seaborne source, supplying the full size grade ladder to exfoliators worldwide through Durban and Richards Bay. |
| China | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest Jan to Dec, arrival Jan to DecLarge concentrate production supplying the domestic construction and horticultural industries and the regional export market. |
| Brazil | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest Jan to Dec, arrival Jan to DecGoias and Piaui production supplying the domestic and South American markets and exporting to Europe. |
| United States | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest Jan to Dec, arrival Jan to DecDomestic concentrate production and a large exfoliation network serving construction and horticulture. |
| Zimbabwe | Harvest | Harvest | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Arrival | Arrival | Harvest Apr to Oct, arrival Jun to DecShurugwi area production moving out through South African and Mozambican ports, weighted to the dry season. | |||
| Uganda | Harvest and arrival | Harvest and arrival | Arrival | Arrival | Harvest | Harvest | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest Jun to Feb, arrival Aug to AprNamekara production shipping through Mombasa, with haulage weighted to the dry months. | |
| Russian Federation | Harvest | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Arrival | Harvest May to Oct, arrival Jun to NovKovdor and Ural production supplying the domestic construction industry, with the open pit season limited by winter. | |||||
| India | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Harvest and arrival | Arrival | Harvest | Harvest and arrival | Harvest and arrival | Harvest Oct to May, arrival Nov to JunAndhra Pradesh and Rajasthan production, with mining and drying weighted to the dry months. |
Windows outside this pattern trade on request, including carry, forward positions and tonnage already sitting in a destination warehouse or terminal.
Customs, packing and contract terms
Indicative terms for vermiculite. Tariff classification is the importer’s responsibility and limits change, so confirm both against the destination customs authority and the current regulation before you fix a contract.
- HS heading2530.10 Vermiculite, perlite and chlorites, unexpanded
- PackingBulk in a lined container, 1 t big bags, or 25 kg to 50 kg paper or PP bags on pallets. Moisture and particle size distribution stated on the certificate of analysis at load.
- Container loading20ft: 26 t to 28 t bulk or big bag. Weight limited well before volume. Check the road weight limit at the destination before fixing the box size.
- Contract and arbitrationSale on typical analysis with a certificate of analysis at load port and an umpire clause. ASTM and API specifications where they exist, including API 13A for drilling grade barite and bentonite. Arbitration under ICC rules or at the contract seat.
- Destination limitsEU REACH registration above one tonne per importer per year, respirable crystalline silica exposure controls under Directive 2017/2398, asbestos screening for talc and vermiculite, NORM screening on heavy mineral products, and food, pharmacopoeia or cosmetic grade certification where the end use requires it.
Common questions
What grades of vermiculite does SIP Global trade?
We quote 44 published grades of vermiculite, including Size grade of the concentrate - Percentage by mass retained at each stated aperture, with the grade named, Top size - Millimetres, maximum, Fines below the stated aperture - Percentage by mass, maximum, Grading of the exfoliated product - Percentage by mass retained at each stated aperture, Median particle size of micron grades - Micrometres and Material state - Declared, as concentrate or exfoliated. Every grade is tied to a delivery point and a settlement route. Grades outside the published list are priced on request.
How is vermiculite graded?
A vermiculite contract turns on the size grade of the concentrate and on how far it exfoliates, because the flake size sets the application and the expansion sets the value of the tonne. Grading runs on 5 systems: Particle size and sizing, Physical properties, Chemical assay, Contaminants and regulated substances and Delivery, documentation and certification.
Where does SIP Global trade vermiculite?
We trade vermiculite in South Africa, China, Brazil, United States, Zimbabwe, Uganda, Kenya and Tanzania, United Republic of and 53 further markets. Origins and destinations outside this list trade on request. We are not limited to the locations shown.
When is vermiculite harvested and when does it arrive?
Typical windows are South Africa: harvest jan to dec, arrival jan to dec; China: harvest jan to dec, arrival jan to dec; Brazil: harvest jan to dec, arrival jan to dec; United States: harvest jan to dec, arrival jan to dec; Zimbabwe: harvest apr to oct, arrival jun to dec. Harvest is when the lot is taken at origin, arrival is when a shipment from that origin lands in a consuming market. Windows outside this pattern, including carry, trade on request.
What is the HS code for vermiculite?
Vermiculite is normally classified under HS 2530.10 (vermiculite, perlite and chlorites, unexpanded). The heading follows the form the goods are in at the border, and national tariffs extend it beyond six digits, so confirm the full line with the destination customs authority before you fix a contract.
How do I get a price for vermiculite?
Send the grade, the origin and the delivery window to the SIP Global desk. That is enough for a trader to come back with a level and a settlement route. 1 listed vermiculite market is published on this page, each with its full specification and terms. We take both sides, physical and financial, prompt to long dated.
Standards and data sources
The grading language on this sheet follows published standards. Trade volumes and tariff lines are public record. Verify anything here against the source.
- ISOInternational Organization for Standardization
- UN ComtradeOfficial international trade statistics by HS code
- ITC Trade MapBilateral trade flows and tariff data
- FAOSTATFAO production and trade series for agricultural commodities
Price this with our desk
Grade, origin and window if you have them. If what you are carrying does not fit the sheet above, describe it in your own words and a trader will take it from there.