Melanite
Image: <a href="//commons.wikimedia.org/wiki/User:Archaeodontosaurus" title="User:Archaeodontosaurus">Didier Descouens</a> (CC BY-SA 4.0)
Mineral NameMelanite
Chemical FormulaCa3(Fe3+,Ti)2(SiO4)3
Mohs Hardness6.5
Crystal Systemcubic
Lustervitreous
Streak Colorwhite
Cleavagenone
Fractureconchoidal
Specific Gravity3.8
Colorsblack
Transparencyopaque
Type LocalityDiakon, Kayes Region, Mali
Mineral GroupSilicates
Usescollector's specimens, minor gemstone
Associated Mineralsnepheline, aegirine, feldspar, titanite
Rarityuncommon
Description
A large, well-formed, black melanite crystal exhibiting a dodecahedral or trapezohedral habit, with a somewhat lustrous surface and some smaller associated crystals or inclusions.
Geological Context
Melanite is a titanium-rich variety of andradite garnet that typically forms in alkaline igneous rocks such as nepheline syenites, phonolites, and carbonatites, crystallizing from magma rich in calcium, iron, and titanium.
