Idocrase (Vesuvianite)
Image: <bdi><a href="https://www.wikidata.org/wiki/Q56247090" class="extiw" title="d:Q56247090"><span title="mineral collector and dealer">Robert M. Lavinsky</span></a></bdi> (CC BY-SA 3.0)
Mineral NameIdocrase (Vesuvianite)
Chemical FormulaCa₁₀(Mg,Fe)₂Al₄(SiO₄)₅(Si₂O₇)₂(OH)₄
Mohs Hardness6.5
Crystal Systemtetragonal
Lustervitreous
Streak Colorwhite
Cleavagepoor on {110} and {100}
Fractureconchoidal to uneven
Specific Gravity3.35
Colorsyellowish-green, purple, pink
Transparencytransparent to translucent
Type LocalityJeffrey mine (Jeffrey quarry; Johns-Manville mine), Asbestos, Les Sources RCM, Estrie, Quebec, Canada
Mineral Groupsilicates
Usesjewelry, ornamental, collector
Associated Mineralsgarnet, diopside, wollastonite, calcite
Rarityuncommon
Description
This specimen features several prismatic, yellowish-green Idocrase (Vesuvianite) crystals, some transparent, growing from a matrix that includes areas of purplish-pink material. The crystals exhibit distinct tetragonal forms and a vitreous luster.
Geological Context
Idocrase (Vesuvianite) typically forms in contact metamorphic environments, particularly in skarns developed from impure limestones or dolomites. It is also found in serpentinites and altered basic igneous rocks.
