Short answers, pulled from the story.
The name pyroxene comes from Ancient Greek words meaning fire and stranger. Early geologists found these crystals embedded in volcanic glass during eruptions and assumed they were unwanted impurities trapped inside molten rock.
Silica tetrahedra form parallel chains where each silicon ion sits surrounded by four oxygen ions creating a tetrahedron shape. Two of those oxygen ions connect to neighboring silicon atoms along the chain while all tetrahedra point in the same direction throughout the mineral lattice.
Twenty mineral names exist today according to the International Mineralogical Association while one hundred five previous names have been discarded over time. Jadeite forms when sodium combines with aluminum on the Y site and omphacite appears when sodium pyroxenes contain more than 20 mol percent calcium magnesium or iron(II).
Clinopyroxenes crystallize in the monoclinic system while orthopyroxenes form orthorhombic crystals. Enstatite exists as three polymorphs including orthoenstatite protoenstatite and clinoenstatite and pigeonite only crystallizes in the monoclinic system regardless of other factors.
The upper mantle of Earth contains mainly olivine and pyroxene minerals while basalt andesite and gabbro rocks consist largely of pyroxene and feldspar. Meteorite ALH84001 from Mars consists mostly of pyroxene minerals and Curiosity rover analysis revealed pyroxenes alongside feldspar and olivine in Martian soil.