CLASS: Carbonate . . . CHEMICAL FORMULA: CaCO3. . . CRYSTAL SYSTEM: Rhombic
CRYSTAL FORM: prism, pinacoid, rhombic bipyramid; pseudohexagonal prisms (composed of twins of 3 rhombic prisms) or in radiated groups, coraloid forms (flos ferri), stalactitic, fibrous, pisolithic.
It has the same chemical formula as Calcite, but a different crystalline structure.
COLOR: colorless, white, yellow, red, brown, blue, green .
PHYSICAL PROPERTIES: semi-hard (3/3,5 Mohs), light (2,95 g/cm3), fragile, difficult to exfoliate in prismatic form, transparent/translucent, vitreous luster, soluble in cold diluted hydrochloric acid with great effervescence.
CURIOSITIES: it is related to the increase of the capacity of resolution of complicated situations.