Gypsum
Gypsum is hydrated calcium sulphate, a soft sedimentary mineral that gives up part of its water when heated and takes it back when mixed with water again, setting into a hard solid. That single property is the basis of plaster, plasterboard and building casts. Gypsum is also interground with clinker in cement manufacture, where it controls the rate at which the cement sets, and it is applied to farmland as a source of calcium and sulphur and to loosen sodic soils. Anhydrite, the water free form, and synthetic gypsum recovered from power station flue gas desulphurisation move in the same trade and against the same specifications.
Listed gypsum markets
Each line is a grade at a delivery point. Open one for its full specification and terms.
Grades
A gypsum contract turns on the purity as calcium sulphate dihydrate, on the impurities that follow it out of the quarry, and on the sizing, because raw rock for a cement mill and calcined plaster for a board line are handled and priced differently.
Chemical assay
12 grades
| Grade | Definition |
|---|---|
| Material typeDeclared, as natural gypsum rock, anhydrite, or synthetic desulphurisation gypsum | The first term on any contract. The three sources behave differently in a kiln and in a cement mill, and each carries its own impurity profile. |
| Calcium sulphate dihydratePercentage by mass | Determined by the combined water method or by X-ray diffraction against the named standard. The payable purity and the headline grade term. |
| Combined waterPercentage by mass | Determined by loss on drying at the temperature stated in the method. It is the direct measure of how much dihydrate is present and it is what the calciner is buying. |
| Calcium sulphate hemihydrate and anhydrite contentPercentage by mass | The partly and fully dehydrated fractions, which change the setting behaviour and are declared where the material has been heated or weathered. |
| Free moisturePercentage by mass, maximum | Determined by oven drying at low temperature. It is fuel cost in the calciner and a handling term at the mill. |
| ChlorideMilligrams per kilogram, maximum | A corrosion term in cement and in board manufacture. Synthetic and seawater influenced gypsum carries the tightest ceiling. |
| Magnesium as magnesium oxidePercentage by mass, maximum | Dolomite and magnesian impurities, penalised in cement grade. |
| Silica as acid insoluble residuePercentage by mass, maximum | The clay and sand that came out of the quarry with the rock. It dilutes the payable sulphate. |
| Calcium carbonatePercentage by mass, maximum | Limestone in the seam. It is tolerated in cement grade and controlled in plaster grade. |
| Sodium and potassium as soluble alkaliPercentage by mass, maximum | Soluble salts that migrate to the surface of a set board and cause efflorescence and paper bond failure. |
| Iron as ferric oxidePercentage by mass, maximum | A colour term, controlled where a white plaster or a white board face is required. |
| pH of a water extractpH units | Determined on a slurry of the stated solids. It governs the additive chemistry on a board line. |
Physical properties
8 grades
| Grade | Definition |
|---|---|
| Setting time of the calcined productMinutes, initial and final set, by the named method | Determined on a standard consistency paste. The defining performance term for plaster and board stucco. |
| Water demand at standard consistencyGrams of water per hundred grams of plaster | How much water the calcined plaster takes to reach a standard flow. It drives the drying energy on a board line. |
| Compressive and flexural strength of the set plasterMegapascals, at the stated age and conditioning | Measured on prisms cast under the named standard. The structural performance of the product the buyer is making. |
| Bulk densityKilograms per cubic metre, loose and tapped | Sets the hold, the silo and the pack. |
| Whiteness and brightnessReported in the CIE colour space, and as ISO brightness under ISO 2470 | Specified where the gypsum goes into a white finishing plaster, a filler or a board face. |
| Hardness and abrasion of the rockReported against the named method | Governs the wear and the throughput in the crusher and the mill. |
| Crystal habit of synthetic gypsumReported by microscopy against the named method | The crystal shape from the desulphurisation plant governs how the filter cake dewaters and how the stucco performs. |
| Deleterious clay and swelling fractionPercentage by mass, maximum | Clay bands in the seam that blind the screens and interfere with set. |
Particle size and sizing
5 grades
| Grade | Definition |
|---|---|
| Sizing of run of quarry and crushed rockMillimetres, as the stated band, with the percentage by mass within band | Determined on screens conforming to ISO 3310. The size band is what the cement mill or the calciner is set up to receive. |
| Top sizeMillimetres, maximum | A hard rejection term because oversize will not pass the feeder. |
| Fines contentPercentage by mass below the stated aperture | Fines create dust and handling loss and are limited on lump grade. |
| Fineness of ground and calcined productPercentage by mass passing the stated aperture, and specific surface area | Determined by sieve and by air permeability. Fineness governs the water demand and the set of the plaster. |
| Particle size distributionMicrometres, by percentile | Determined by laser diffraction under ISO 13320 for fine ground and filler grades. |
Contaminants and regulated substances
7 grades
| Grade | Definition |
|---|---|
| Heavy metalsMilligrams per kilogram, maximum, by element | Mercury, cadmium, lead, arsenic, selenium and thallium. Synthetic desulphurisation gypsum carries element by element ceilings because the flue gas concentrates them. |
| FluorideMilligrams per kilogram, maximum | Relevant to phosphogypsum and to some synthetic sources, and a rejection term where present above the limit. |
| RadionuclidesBecquerels per kilogram | Screened where the source is phosphogypsum or where the destination sets a building material activity index. |
| Ammonia and residual amineMilligrams per kilogram, maximum | A synthetic gypsum term. Residual ammonia is released in the calciner and on the board line. |
| Dioxins and organic residuesMilligrams per kilogram, maximum | Screened on synthetic material where the destination requires it. |
| Construction product conformityDeclared | The conformity route and marking required at the destination for a construction material, named on the contract. |
| Agricultural and food chain complianceDeclared | Where the gypsum is applied to land or enters the food chain, the applicable fertiliser or additive regulation is named. |
Delivery, documentation and certification
9 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. |
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 |
|---|---|---|
| China | East Asia | Origin and destination |
| United States | North America | Origin and destination |
| Iran | Middle East | Origin and destination |
| Turkiye | Europe and Anatolia | Origin and destination |
| Spain | Southern Europe | Origin and destination |
| Thailand | Southeast Asia | Origin and destination |
| Oman | Middle East | Origin and destination |
| Saudi Arabia | Middle East | Origin and destination |
| United Arab Emirates | Middle East | Destination and trading hub |
| Mexico | North America | Origin and destination |
| Canada | North America | Origin and destination |
| Italy | Southern Europe | Origin and destination |
| France | Western Europe | Origin and destination |
| Germany | Western Europe | Destination |
| United Kingdom | Northern 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 |
| Russian Federation | Eurasia | Origin and destination |
| Kazakhstan | Central Asia | Origin and destination |
| Greece | Southern Europe | Origin and destination |
| Portugal | 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 |
| Kenya | East Africa | Origin and destination |
| Tanzania, United Republic of | East Africa | Origin and destination |
| Uganda | East Africa | Origin and destination |
| Mozambique | Southern Africa | Origin and destination |
| South Africa | Southern Africa | Origin and destination |
| Namibia | Southern Africa | Origin and destination |
| Zimbabwe | Southern Africa | Origin and destination |
| Brazil | South 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 |
| India | South Asia | Origin and destination |
| Pakistan | South Asia | Origin and destination |
| Sri Lanka | South Asia | Origin and destination |
| Viet Nam | Southeast Asia | Origin and destination |
| Indonesia | Southeast Asia | Origin and destination |
| Malaysia | Southeast Asia | Origin and destination |
| Japan | East Asia | Destination |
| Korea, Republic of | East Asia | Destination |
| Singapore | Southeast Asia | Trading and finance |
| Switzerland | Western Europe | Trading and finance |
| Qatar | 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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 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 DecThe largest producer, with output following construction demand and the desulphurisation programme at the coal fired fleet rather than a season. |
| Iran, Islamic Republic of | 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 DecA large quarrying and export sector serving the Gulf and South Asian markets. |
| Oman | 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 dominant seaborne exporter to India, East Africa and Southeast Asia, shipping through Salalah and the northern ports. |
| Thailand | 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 DecQuarry production supplying the regional cement and board industry, shipping through the Gulf of Thailand ports. |
| Spain | 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 quarry production supplying Europe and West Africa, with the Mediterranean and Atlantic ports both used. |
| 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 DecNatural quarry production and a very large synthetic desulphurisation supply from the power sector, feeding the domestic board industry. |
| Turkiye | 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 DecQuarry and processed plaster production exporting across the Mediterranean and the Black Sea. |
| Mexico | 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 DecBaja California and Gulf coast quarry production shipping to North America and Asia. |
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 gypsum. 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 heading2520.10 Gypsum and anhydrite
- 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 gypsum does SIP Global trade?
We quote 41 published grades of gypsum, including Material type - Declared, as natural gypsum rock, anhydrite, or synthetic desulphurisation gypsum, Calcium sulphate dihydrate - Percentage by mass, Combined water - Percentage by mass, Calcium sulphate hemihydrate and anhydrite content - Percentage by mass, Free moisture - Percentage by mass, maximum and Chloride - Milligrams per kilogram, maximum. Every grade is tied to a delivery point and a settlement route. Grades outside the published list are priced on request.
How is gypsum graded?
A gypsum contract turns on the purity as calcium sulphate dihydrate, on the impurities that follow it out of the quarry, and on the sizing, because raw rock for a cement mill and calcined plaster for a board line are handled and priced differently. Grading runs on 5 systems: Chemical assay, Physical properties, Particle size and sizing, Contaminants and regulated substances and Delivery, documentation and certification.
Where does SIP Global trade gypsum?
We trade gypsum in China, United States, Iran, Turkiye, Spain, Thailand, Oman and Saudi Arabia and 51 further markets. Origins and destinations outside this list trade on request. We are not limited to the locations shown.
When is gypsum harvested and when does it arrive?
Typical windows are China: harvest jan to dec, arrival jan to dec; Iran, Islamic Republic of: harvest jan to dec, arrival jan to dec; Oman: harvest jan to dec, arrival jan to dec; Thailand: harvest jan to dec, arrival jan to dec; Spain: harvest jan to dec, arrival jan 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 gypsum?
Gypsum is normally classified under HS 2520.10 (gypsum and anhydrite). 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 gypsum?
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 gypsum 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.