labradorite
Noun
Meaning
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.
Source: Webster's dictionarySynonyms
Examples
The calcium rich plagioclase feldspar ( labradorite bytownite ) and pyroxene content vary between 10% - 90% in gabbro.
The gemstone commonly called rainbow moonstone is more properly a colorless form of labradorite and can be distinguished from "true" moonstone by its greater transparency and play of color, although their value and durability do not greatly differ.
Feldspar phenocrysts typically are labradorite to andesine in composition.