Labradorite n. : A kind of feldspar commonly showing a beautiful play of colors, and hence much used for ornamental purposes. The finest specimens come from Labrador. See Feldspar.

Example:
What is the difference of an andesine Labradorite and a regular Labradorite gem?

Taxonomy
Labradorite, iridescence, free encyclopedia, ranges, crystal system, streak, search, characteristics, calcic, silicates, right angle, prisms, lath, grains, plagioclase series, geological, type area, masses.

Defination from the web:
labradorite is Paul's Island near the town of Nain in Labrador, Canada. ... Gemstone varieties of labradorite exhibiting a high degree of iridescence are called spectrolite; moonstone and sunstone are also commonly used ...