mineral
Labradorite
Plagioclase Feldspar (Na,Ca)(Al,Si)4O8
Hardness of 6 to 6.5 on the Mohs scale, grayish to dark gray base color, exhibits labradorescence (iridescent flashes of blue, green, gold, and orange), vitreous to pearly luster, triclinic crystal system, good cleavage.
Identified More mineral →
Explore Labradorite in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness of 6 to 6.5 on the Mohs scale, grayish to dark gray base color, exhibits labradorescence (iridescent flashes of blue, green, gold, and orange), vitreous to pearly luster, triclinic crystal system, good cleavage.
Formation & geological history
Forms in mafic igneous rocks such as basalt, gabbro, and anorthosite through slow cooling of magma deep within the Earth's crust or in metamorphic and pegmatitic environments.
Uses & applications
Widely used in ornamental objects, jewelry (cabochons and beads), and as a dimension stone due to its striking optical phenomenon.
Geological facts
Labradorite was first discovered on Paul Island in Labrador, Canada, in 1770, and is famous for its unique optical phenomenon called labradorescence, caused by light interference in lamellar intergrowths.
Field identification & locations
Easily identified by its dark gray appearance in normal light and brilliant, colorful flashes of metallic play-of-color when tilted at specific angles. Found notably in Canada, Madagascar, Finland, and Australia.
More like this
Other mineral specimens
Sandstone (with potential mineral staining/concretions)
Arenite (SiO2 based)
sedimentary
Soil with Mineral Detritus and Quartz Fragments
Regolith / Silicate Mineral Aggregate
sedimentary
Limonite / Goethite (Iron Ore Mineral nodule)
FeO(OH)·nH2O / FeO(OH)
mineral
Schist
Schist
Metamorphic
Septarian Pebble
Septarian nodule / Concretion
sedimentary
Potassium Feldspar (Orthoclase)
Orthoclase (KAlSi3O8)
mineral