Calcium carbonate naturally exists in forms including limestone, marble, chalk and coral, and is widely applied in construction-related industries for manufacturing cement, plaster and glass. It can also be used to produce quicklime, hydrated lime and various calcium-based compounds. It is available in powdered and precipitated grades; the precipitated type features higher purity and finer particle size, suitable for applications in textiles, paper, paints, plastics and cosmetics.
Calcium carbonate occurs in two crystalline forms: calcite (hexagonal) and aragonite (orthorhombic). Calcite decomposes at 825°C, while aragonite melts at 1339°C. It is insoluble in water but soluble in dilute acids.
This compound is abundant in the Earth's crust, with calcite as the most prevalent form. Its crystalline variants depend on formation conditions, and vaterite presents a rare polymorph.
Calcium Carbonate Chemical Properties
Melting point | 825 °C |
Boiling point | 800 °C |
density | 2.93 g/mL at 25 °C (lit.) |
refractive index | 1.6583 |
storage temp. | Store at +5°C to +30°C. |
solubility | 5 M HCl: 0.1 M at 20 °C, clear, colorless |
form | random crystals |
color | White-beige to slightly beige-gray |
Specific Gravity | 2.93 |
PH | 9.91(1 mM solution);9.91(10 mM solution);9.91(100 mM solution); |
Odor | Odorless |
PH Range | 8 |
Water Solubility | Insoluble |
λmax | λ: 260 nm Amax: ≤0.09 |
Merck | 14,1657 |
BRN | 8008338 |
Solubility Product Constant (Ksp) | pKsp: 8.54 |
Exposure limits | NIOSH: TWA 10 mg/m3; TWA 5 mg/m3 |
Dielectric constant | 6.1（Ambient） |
Stability: | Stable. Incompatible with acids, fluorine, ammonium salts, alum. |
InChIKey | VTYYLEPIZMXCLO-UHFFFAOYSA-L |
CAS DataBase Reference | 471-34-1(CAS DataBase Reference) |
EPA Substance Registry System | Calcium carbonate (471-34-1) |
Safety Information
Hazard Codes | Xi |
Risk Statements | 37/38-41-36/38-36 |
Safety Statements | 26-36/37/39-37/39-37 |
OEB | B |
OEL | TWA: 10 mg/m3 (total) |
WGK Germany | - |
RTECS | FF9335000 |
TSCA | Yes |
HS Code | 28365000 |
Hazardous Substances Data | 471-34-1(Hazardous Substances Data) |
Toxicity | LD50 orally in Rabbit: 6450 mg/kg LD50 dermal Rat > 2000 mg/kg |
