Member of the garnet group of minerals, Mg3Al2(SiO4)3; sp. gr. 3.51; hardness 6.0–7.5; cubic; dark red, pink-red, or black; vitreous lustre; crystals (dodecahedra, also occurs massive; occurs in high-grade metamorphic rocks (e.g. eclogites) and deep-seated igneous rocks (e.g. garnet peridotites), which are often mantle derived, although the pyrope molecule occurs to a variable extent in most almandines; it is also distributed in alluvial deposits. Transparent crystals are used as gemstones. The name is derived from the Greek puropos, meaning ‘fiery eyed’.
Subjects: Earth Sciences and Geography.