Doğada kireç taşı, tebeşir ve mermer gibi kayaçlarda en yaygın bulunan, endüstride ve laboratuvarlarda çok geniş bir kullanım alanına sahip temel bir inorganik bileşiktir.
 
Linear Formula: CaCO₃
CAS Number: 471-34-1
Molecular Weight: 100.09
UNSPSC Code: 12352302
NACRES: NA.21
EC Index Number: 207-439-9
MDL number: MFCD00010906
Beilstein/REAXYS Number: 8008338
eCl@ss: 38110301
Assay: 98.5-100.5% dry basis (complexometric)
Form: solid
Agency : reag. Ph. Eur.
Quality Segment : 300
Product line : EMSURE^®
Assay : 98.5-100.5% dry basis (complexometric)
Form : solid
Potency : 6450 mg/kg LD₅₀, oral (Rat), >2000 mg/kg LD₅₀, skin (Rat)
İmpurities : ≤0.005% Substances insoluble in hydrochloric acid, ≤0.2% Substances insoluble in acetic acid
Loss : ≤ 1.0% loss on drying, 200 °C
Particle size : ~14 μm (D 50)
Ph : 9.5-10.5 (20 °C, 100 g/L in H₂O, slurry)
Mp : 825 °C (decomposition)
Density : 2.93 g/mL at 25 °C (lit.)
Bulk density : 300‑1400 kg/m³
Anion traces : chloride (Cl^-): ≤0.005%, sulfate (SO₄^2-): ≤0.03%
Cation traces Al:  ≤0.005%, As: ≤0.0004%, Ba:, passes test, Cu: ≤0.0005%, Fe: ≤0.001%, K: ≤0.005%, Mg: ≤0.02%, Mg and allied cations: ≤1.5%, N: ≤0.001%, Na: ≤0.2%, Pb: ≤0.0005%, Sr: ≤0.1%, heavy metals (as Pb): ≤0.002%
Storage temp. : 10-30°C