Raw Gypsum Rock Supplier & Exporter
CaSO₄·2H₂O Calcium Sulfate Dihydrate · 88 – 99%
Natural gypsum rock in four purity grades from 88% cement grade to 99% premium white, crushed to 0–50 mm lump for cement set retardation, plaster calcination, plasterboard manufacture and agricultural soil conditioning. Analysed to ASTM C471-M-20, with a batch-specific Certificate of Analysis per shipment.
Purity up to 99%
Physical Properties
Formula
CaSO₄·2H₂O
Molecular Weight
172.17 g/mol
Mohs Hardness
2.0
Specific Gravity
2.31 – 2.33
Combined Water
18 – 20.9%
Standard Size
0 – 50 mm
Synonyms: Gypsum Rock, Raw Gypsum, Calcium Sulfate Dihydrate, Land Plaster, Cement Retarder · White to pale grey crystalline rock; soft enough to scratch with a fingernail.
Grades & Chemical Analysis
Four raw gypsum grades to match your process — from cement-plant retarder through to premium white feedstock for plaster and filler. Select a grade to view its full analysis.
Premium White — Highest analysed purity
Premium 99
- CaSO₄·2H₂O Purity
- 99.0%
- SO₃
- 45.64%
- CaO
- 31.96%
- SiO₂
- 0.43%
- MgO
- 0.082%
- Moisture (free water)
- 0.07%
- Size −50 mm
- 93.75%
- Size +50 mm
- 6.25%
- Form
- Lump
- Test Method
- ASTM C471-M
Analysis by ASTM C471-M-20 (chemistry) and ASTM C136 (size grading). Purity in a natural deposit varies with the working face and with each blast, so a current sample analysis is issued for every consignment rather than a standing certificate.
Cement Grade — Representative Mine-Face Analyses
Three certificates taken from different working faces of the same deposit. They are published as-tested so you can see the real spread rather than a single averaged figure.
| Parameter | Sample A | Sample B | Sample C |
|---|---|---|---|
| Purity (CaSO₄·2H₂O) | 88.06% | 90.83% | 92.14% |
| Combined Water | 18.22% | 19.01% | 19.28% |
| SO₃ | 44.12% | 44.12% | 42.84% |
| CaO | 30.01% | 32.47% | 30.01% |
| SiO₂ | 0.25% | 1.05% | 0.47% |
| MgO | 0.88% | 0.88% | 1.12% |
| Fe₂O₃ | 1.18% | — | 0.05% |
| Al₂O₃ | 0.05% | — | 0.05% |
| R₂O₃ | 0.64% | 0.64% | — |
| Free Moisture | — | 0.38% | 0.79% |
| Chloride | — | 0.01% | — |
| Size 0 – 50 mm | 100% | 100% | 100% |
A fourth face analysed at purity above 90% with SO₃ 46.33%, CaO 32.30%, SiO₂ 0.06%, Na₂O 0.02%, K₂O 0.01% and L.O.I. 20.85%. All testing to ASTM C471-M-20.
Bespoke Production
Need a different purity or size?
If none of the grades above matches your target chemistry, fineness, or packaging, tell us your requirements — we produce custom grades to your exact specification.
Applications
Raw gypsum is one of the few minerals that goes straight from the pit into three completely different industries with barely any processing.
Cement Set Retardation
The standard 3–5% addition that controls C₃A hydration in Portland cement.
Plaster & Plasterboard
Feedstock for calcination into stucco and wallboard.
Agricultural Soil Conditioner
Reclaims sodic soils and supplies calcium and sulfur without shifting pH.
Sulfuric Acid Manufacture
Sulfur source in the Muller-Kuhne process.
Paint & Filler
White extender in paints, plastics and rubber.
Ceramic & Dental Moulds
Casting and impression moulds after calcination.
Paper & Textile
Filler and coating mineral.
Water Treatment
Calcium and sulfate source in process water conditioning.
Glass & Fertilizer
Batch component and calcium-sulfur fertilizer base.
Packaging, Logistics & Trading Terms
How we size, certify and ship raw gypsum. Terms can be adapted by agreement — tell us what your operation needs.
- Minimum Order Quantity
- 1 × 20 ft container (approx. 25 MT) bagged. 500 MT minimum for bulk vessel. Trial quantities available for qualification.
- Packaging
- Raw rock in bulk or 1–1.5 MT jumbo bags; plaster in 25 kg 3-ply laminated PP bags or jumbo bags. Moisture-proof PE lining available on request.
- Incoterms & Loading Ports
- EXW, FOB, CFR and CIF (Incoterms® 2020). Standard loading at Bandar Abbas and Bandar Imam Khomeini; other ports by arrangement.
- Quality Certification
- Batch-specific CoA with every shipment covering purity as CaSO₄·2H₂O, combined water, SO₃ and oxide impurities. SGS / Bureau Veritas inspection at buyer’s cost.
- Lead Time
- 7–14 days for standard grades after order confirmation; 15–25 days for custom-milled or specially packed material.
- Storage & Handling
- Store dry and covered. Gypsum is stable but hygroscopic in powder form — keep plaster bags sealed and off the ground, as absorbed moisture starts pre-hydration and shortens working time.
Certificate of Analysis
A batch-specific CoA is issued with every shipment. Third-party inspection by SGS, Bureau Veritas or an inspector of your choice can be arranged at the buyer’s cost.
Ready to quote
Send us your grade, tonnage, destination port and packaging and we will return a firm FOB/CFR/CIF price with lead time.
Request a Raw Gypsum Quote