Anorthites

Part of speech: noun

Definitions

1. A type of mineral belonging to the feldspar group, characterized by its composition primarily of calcium-rich plagioclase
2. A crystalline form of plagioclase feldspar that contains a significant amount of anorthite, making it key in geological studies
3. A specific mineral often found in igneous rocks, notable for its high calcium content and role in petrology

Etymology: "Anorthites" is simply the plural of "anorthite," the name of a calcium-rich feldspar mineral found in igneous rocks such as gabbro and anorthosite. The mineral's name is built from Ancient Greek: the prefix "an-" meaning "not," joined to "orthos," meaning "straight." The name refers to the crystal structure, which is oblique rather than right-angled. Its crystals do not meet at the perpendicular angles that the name's ancestor, the "orthoclase" family of feldspars, is known for, so the name describes what the mineral lacks.