Oyster shell calcium carbonate is not a unique chemical type of calcium. It is mainly calcium carbonate, but calcium from oyster shell. Oyster shell facts that it is a natural source of calcium. Calcium carbonate is the active ingredient in agricultural lime and is created when calcium ions in hard water react with carbonate ions to create limescale. It is medicinally used as a calcium supplement or as an antacid, but excessive consumption can be hazardous and cause poor digestion

General Characteristics


Product Calcium Carbonate Oyster shell
Grade JP
Properties Specification Result
Description A White, Fine, Microcrystalline Powder Complies
Solubility Practically insoluble in water and in ethanol (95%), slightly soluble in water containing carbon dioxide or any ammonium salt. It is soluble with dilute acids Complies
Identification (A)Reaction A and B of Calcium Salt (B)Reaction A of Carbonates (i)Reaction A of Calcium Salts: A White, Crystalline Precipitate should be formed (ii)A White Precipitate should be obtained that is only sparingly soluble in dilute acetic but is soluble in hydrochloric acid A White precipitate should be formed that dissolves on addition of an excess of dilute hydrochloric acid Complies Complies Complies
Substances insoluble in acetic acid The residue should weigh not more than 10 mg 7 mg
Arsenic Not more than 4 ppm 3 ppm
Heavy Metals Not more than 20 ppm 13 ppm
Barium The solution should remain clear for not less than 15 minutes Complies
Iron Not more than 200 ppm 166 ppm
Magnesium and alkali Metals The residue weighs not more than 5 mg 3 ppm
Chloride Not more than 250 ppm 188 ppm
Sulphates Not more than 0.3% 0.1%
Loss on Drying (at 2000C) Not more than 2.0%w/w 1.5%w/w
Assay (By Titrimetry) It should contain not less than 98.0% and not more than 100.5% of CaC03 calculated on the dry’s basis 100.2%
Visible Foreign & Black Particles The material should be free from visible foreign/ black particles Complies
Particles Size Not less than 99.0% should pass through 100 mesh Complies
Bulk Density Tapped density: Not less than 0.80 g/mL 0.89 g/mL

Microbiological Analysis

Total Aerobic microbial count Total yeast and mold count Escherichia Coli Salmonella Pseudomonas Aeruginosa Salmonella Staphylococcus aureus 1,000 cfu/g 100 cfu/g Absent/g Absent/ 10g Absent/g Absent/g Complies Complies Complies Complies Complies Complies