Calcite (CaCO3, calcium carbonate) from Manresa. Calcite is a mineral that crystallizes in several shapes, producing crystals generally white or colorless, although sometimes they can be different colors. Calcite defines the third degree of hardness of Moh’s scale. It cannot be scraped by the nail, but it is easily scraped by a knife.
Crystalls of calcite result from the deposit of water containing calcium carbonate. Calcite crystals are often found coating the cracks of CaCO3 containing stones and in caves. The pictures below display one crack of the sandtone filled with crystalls of calcite, in an old quarry in Malbalç (Manresa). This type of mineralization is frequent in the district of Bages.
Calcite is the main component of limestones that are used in the manufacture of cement and lime.

[photos Joaquim Sanz / Museum of Geology Valentí Masachs (1st), Florenci Valles (2nd) and Jordi Badia (3rd)]