Blue calcite from Mexico
You will be picked on at random.
Sizes-
7.7cm x 4.8cm - 5.9cm x 5.1cm
Weights-
100g - 164g
Blue calcite gets its blue colour from trace impurities and mineral inclusions. Most commonly copper ions substituting for calcium in the crystal lattice or microscopic inclusions of Aurichalcite (a copper -zinc carbonate mineral)
Crystal system- Trigonal
Mineral class- Carbonate
Hardness- 3 on the MOHs scale
Rock formation-
Sedimentary- it precipitates directly from calcium-rich water in marine settings,limestone caves and evaporite deposits.
Metamorphic- When limestone undergoes regional or contact metamorphism,the calcite recrystallises into marble. Blue calcite is frequently harvested from coarse-grained m,bluish-grey or sky blue calcite marbles.
Hydrothermal veins- It crystallises from hot mineral rich fluids circulating through fractures and cavities in igneous or metamorphic host rocks often alongside quartz,fluorite and sulphide minerals.
