Labradorite is a feldspar mineral of the plagioclase. It is most
often found in mafic igneous rocks such as basalt, and gabbro. Most
specimens have an iridescent blue, green, red, orange, and yellow.
It comes from Madagascar. It measures at: 4in X 2 1/2in. X 1 3/8in.
Physical Properties of Labradorite
Usually clear, white, or gray in reflected light. Labradorescent colors can include blue, green, yellow, orange, and red.
Vitreous, pearly on cleavage faces
Transparent to translucent
Two directions of perfect cleavage intersecting at about 86 degrees
6 to 6.5
2.68 to 2.72
Hardness, cleavage (twinning and labradorescence are only shown by some specimens)
with Na (30-50%) and Ca (70-50%)