Labradorite

Labradorite is a mineral from the plagioclase feldspar group, composed mainly of sodium and calcium silicate ((Ca,Na)(Al,Si)₄O₈). It is famous for its adularescence phenomenon, called labradorescence, which reveals metallic flashes of blue, green, yellow, orange, or violet depending on the orientation of the light. Formed in igneous rocks, particularly gabbros and anorthosites, it generally occurs as masses or crystals.

Specimens from Madagascar, Canada, and Finland are particularly known for their magnificent play of colors and spectacular reflections.