Pyrope

Formula: Mg₃Al₂(SiO₄)₃

Origin of name: from Greek pyropos = fiery

Crystal system: cubic

Crystal class: 4/m -3 2/m

Twinning: 

Unit cell: a = 11.46 Å

Colour: pinkish red, purplish red, orange-red

Diaphaneity: 

Luster: vitreous

Habit: 

Hardness: 7 to 7.5

Specific gravity: 3.5 to 3.8

Cleavage: 1; {110} parting, sometimes distinct

Tenacity: 

Streak: white

Synonyms/varieties: carbuncle, rhodolite (purple-red gem variety)

Comments: series with almandine, with spessartine and with knorringite