GCC, PCC and coated in one range
Four calcium carbonate grades, from general-purpose filler to stearic-coated PVC grade, so formulators can source and qualify one supplier across products.
Industrial Mineral
Calcium Carbonate — GCC, PCC and Coated Grades from India
Ground, precipitated and surface-treated calcium carbonate with controlled particle size and brightness for paints, plastics, rubber and construction formulations.
GCC PowderPCC PowderCoated (stearic acid treated)
ISO 9001 certified processes
NABL-accredited lab testing
CoA, TDS & MSDS with every shipment
Export packaging worldwide
Overview
What is Calcium Carbonate?
Calcium carbonate, CaCO₃, is the most widely used mineral filler in industry. Ground calcium carbonate (GCC) is produced from natural calcite-rich limestone and marble, while precipitated calcium carbonate (PCC) is made chemically by reacting slaked lime with carbon dioxide under controlled conditions. Both share the same chemistry but differ in particle shape, size and purity, and those differences decide where each one performs best.
Calcite is soft, at about 3 on the Mohs scale, so it is gentle on extruders, mixers and dies. It is chemically stable in neutral and alkaline systems, bright white, and has a refractive index close to that of many binders and polymers. That makes it an efficient extender rather than a hiding pigment. Formulators use it to add volume, improve processing and stiffness, and lower the cost of the finished compound or paint.
Fineness drives performance. Standard GCC suits putties, adhesives, rubber and general-purpose fillers. Fine GCC with a median size below 5 µm is used where gloss, smoothness and mechanical properties matter. PCC offers higher brightness and a narrow, very fine size distribution for paper and premium coatings. Stearic-acid-coated grades turn the naturally hydrophilic surface hydrophobic, so the filler disperses well in PVC, polyolefins and sealants.
Obsidian Minerals supplies calcium carbonate from manufacturing sites in Gujarat and Rajasthan under ISO 9001 certified processes, with NABL-accredited laboratory testing. Each shipment includes a Technical Data Sheet, MSDS/SDS and batch Certificate of Analysis. Grades are packed in 25 kg or 50 kg bags or in 1 MT and 1.2 MT jumbo bags, and samples and custom particle sizes are available on request.
Calcium Carbonate grades
Select a grade for its typical properties, applications, usage guidance and FAQs.
Calcium Carbonate
GCC Standard Grade
Ground calcite filler with dependable brightness and controlled top size for high-volume construction, rubber and coating formulations.
General purpose filler Calcium CarbonateGCC Fine Grade
Finely classified ground calcite for formulations where gloss, smoothness and mechanical properties depend on particle size.
High-quality paints and plastics Calcium CarbonatePCC Grade
Synthetic calcium carbonate with high brightness and fine, uniform crystals for paper and premium coating formulations.
Paper and premium coatings Calcium CarbonateCoated Grade
Hydrophobic, surface-treated calcium carbonate that disperses cleanly in PVC, polyolefins and sealants at high loadings.
Plastics and PVC| Grade | Specification | Primary use | Link |
|---|---|---|---|
| GCC Standard Grade Calcium Carbonate | On TDS | General purpose filler | Specs |
| GCC Fine Grade Calcium Carbonate (D50 < 5 µm) | D50 < 5μm | High-quality paints and plastics | Specs |
| Precipitated Calcium Carbonate (PCC) | On TDS | Paper and premium coatings | Specs |
| Coated Calcium Carbonate (Stearic Acid Treated) | On TDS | Plastics and PVC | Specs |
From deposit to dispatch
- 01
Selective mining of high-purity calcite
- 02
Crushing, washing and sorting
- 03
Grinding and air classification (GCC) or controlled precipitation (PCC)
- 04
Stearic acid surface coating (coated grade)
- 05
QC testing and packing
Why source Calcium Carbonate from Obsidian Minerals
Particle size control
Air classification and routine particle size testing keep median size and top cut consistent from batch to batch, supporting stable viscosity and surface finish.
Documented supply
Sites in Gujarat and Rajasthan, ISO 9001 certified processes, NABL-accredited testing and a CoA with every batch, supplied to customers in 15+ countries.
Where Calcium Carbonate is used
Calcium Carbonate — frequently asked questions
What is the difference between GCC and PCC?
GCC, or ground calcium carbonate, is natural calcite that has been crushed, milled and classified. PCC, or precipitated calcium carbonate, is produced chemically from lime and carbon dioxide. PCC is generally brighter, purer and finer, with a narrower size distribution and higher oil absorption. GCC is more economical and has lower binder demand, so it is used in larger volumes.
What is coated calcium carbonate?
Coated calcium carbonate is fine GCC whose particle surfaces have been treated with stearic acid. The treatment makes the powder hydrophobic, so it wets into polymers and plasticisers instead of attracting moisture. It is the usual choice for PVC pipes and profiles, cable compounds, filler masterbatch and many sealants, where uncoated filler would agglomerate or raise melt viscosity.
Which calcium carbonate grade should I use for PVC?
For rigid PVC pipes, profiles and fittings, and for flexible cable and flooring compounds, the stearic-acid-coated grade is normally recommended because it disperses better and adds less moisture. Fine uncoated GCC can be used in some formulations at lower loadings. Final filler levels should follow your compound design and any product standard that applies to the finished article.
What brightness does your calcium carbonate have?
Typical GE brightness ranges from about 92 for the standard GCC grade to 96 or higher for PCC, with the fine and coated grades in between. Brightness depends on the raw material and fineness. The value for each grade is stated on its Technical Data Sheet and the measured figure appears on every batch Certificate of Analysis.
How is calcium carbonate packed for export?
Calcium carbonate is packed in 25 kg or 50 kg HDPE or paper bags, or in 1 MT and 1.2 MT jumbo (FIBC) bags for bulk users. Fine and coated grades can be supplied in lined bags to protect against moisture. Custom bag weights and private-label packaging are available on request, with TDS, MSDS/SDS and CoA for each consignment.
Can you develop a custom particle size?
Yes. Median particle size, top cut and, for the coated grade, coating level can be adjusted to suit a specific formulation. Share your current material's data sheet or target values, and a trial sample can be produced for evaluation. Custom grades are confirmed with their own Technical Data Sheet once approved.
What packaging options are available for Calcium Carbonate?
Standard export packing is 25 kg or 50 kg HDPE / paper bags and 1 MT or 1.2 MT jumbo (FIBC) bags, palletised and shrink-wrapped on request. Custom and private-label packaging can be arranged for volume orders.
Do you provide MSDS and technical datasheets?
Yes. A Technical Data Sheet and MSDS are available for every grade, and each shipment is accompanied by a batch-specific Certificate of Analysis.
Request a quote
Interested in Calcium Carbonate?
Tell us your application, preferred grade and volume. Our engineering team will recommend the right grade and send a datasheet, sample and quotation.
- Technical Data Sheet & MSDS
- Samples for qualification trials
- Bulk and recurring supply pricing