Vesuvianite sits at 6.5 on the Mohs scale —
harder than glass; scratches steel.
Colors:
Streak White
Crystal system Tetragonal
Type localityMt. Vesuvius, Naples, Italy
SilicatesSilicates (Sorosilicates)
TL;DR · 1 min read
Vesuvianite (Ca₁₀(Mg,Fe)₂Al₄(SiO₄)₅(Si₂O₇)₂(OH)₄), historically called "idocrase," is a calcium-magnesium-aluminum sorosilicate that forms in contact-metamorphic skarns. It was first described in 1795 from blocks ejected by Mount Vesuvius, hence the name.
Vesuvianite (Ca₁₀(Mg,Fe)₂Al₄(SiO₄)₅(Si₂O₇)₂(OH)₄), historically called “idocrase,” is a calcium-magnesium-aluminum sorosilicate that forms in contact-metamorphic skarns. It was first described in 1795 from blocks ejected by Mount Vesuvius, hence the name. Color ranges from common olive-green and brown through rare blue (“cyprine,” with copper) and green-yellow gem material — the “californite” jade-substitute variety from California, and the cyprine variety from Norway are particular collector targets.