Emerald
Image: Didier Descouens (CC BY-SA 3.0)
Mineral NameEmerald
Chemical FormulaBe₃Al₂Si₆O₁₈
Mohs Hardness7.5
Crystal Systemhexagonal
Lustervitreous
Streak Colorwhite
Cleavageimperfect basal
Fractureconchoidal
Specific Gravity2.72
Colorsgreen
Transparencytransparent
Type LocalityMuzo Mine, Colombia
Mineral GroupSilicates
Usesjewelry, collector
Associated Mineralscalcite, pyrite, quartz, shale
Rarityrare
Description
A vibrant green, prismatic emerald crystal, approximately 2cm long, embedded in a white crystalline matrix with dark and golden metallic specks.
Geological Context
Emeralds are typically found in metamorphic rocks or pegmatites. Colombian emeralds, like this one from Muzo, are unique, forming in black shales and limestones through low-temperature hydrothermal processes, often associated with tectonic activity.
