3" Pink Thulite Formation - Mjønes, Norway

Zoisite belongs to the epidote group of minerals with the chemical formula Ca2Al3(SiO4)(Si2O7)O(OH) (calcium aluminium hydroxy sorosilicate). It can be found in a variety of colors including green, pink, brown, yellow, grey, white, blue, purple or colorless. The color it bears depends on the ion substitutions within the crystal lattice. For example, thulite is a pink variety of zoisite that gains its pink color from manganese substituting for calcium within the crystal lattice, and tanzanite is a blue-violet variety of zoisite that gains its color from the substitution of vanadium. Zoisite was originally known as saualpite.