Melanite

Melanite is a rare variety of garnet, specifically a titanian andradite. It belongs to the andradite group, which is the most complex of the garnet group minerals. Its defining characteristic is its dark color, typically black, very dark brown, or deep reddish-brown, which gives it its name, derived from the Greek word "melas" meaning black. The dark hue is primarily due to the presence of titanium, which substitutes for aluminum in the crystal structure.

Physically, melanite is a vitreous mineral with a hardness of 6.5 to 7 on the Mohs scale. It crystallizes in the cubic system, often forming dodecahedral or trapezohedral crystals. While it can occur in various geological settings, it is most commonly found in alkaline igneous rocks, such as nepheline syenites and melanephelinites. It is also occasionally found in metamorphosed limestones and contact metamorphic zones.

Gemological interest in melanite is limited due to its rarity and often opaque nature, which makes it unsuitable for faceting. However, translucent to transparent specimens, though uncommon, can be cut and polished. Its diagnostic feature is its dark color and its occurrence in specific geological environments. Notable occurrences have been reported in regions like Italy, Russia, and the United States.