You searched for: “oligoclase
oligoclase
A kind of plagioclase feldspar occurring commonly in white crystals, sometimes shaded with gray, green, or red.

Plagioclase refers to any of a series of common feldspar minerals, consisting of differing mixtures of sodium and calcium aluminum silicates.

Plagioclase is typically white, yellow, or reddish-gray, but it can also be blue to black. It occurs in igneous rocks.

The minerals albite, oligoclase, andesine, labradorite, bytownite, and anorthite are all plagioclases.