Uvite was considered to be a very rare member of the Tourmaline
Group, but it is now becoming widely available on the mineral markets.
Other more common and more well-known tourmalines are schorl
(black, opaque and iron rich) and elbaite
(various colors, transparent to translucent, used as a gemstone and lithium
rich). less common tourmalines are dravite,
Uvite is the magnesium/iron-rich member of the group and has one notable exception to the typical tourmaline generalized formula. The usual 6 aluminums are reduced to 5, with a magnesium inserted into one of the aluminums' positions. Despite having so many coloring ions like iron and magnesium, some specimens of uvite can be colorless. The typical specimens of uvite on the mineral markets tend to be an interesting dark green to almost black in color. Other properties of uvite seem to fall in the norm for a tourmaline, except uvite tends to form stubby crystals rather than the long prismatic crystals of its close cousins. These crystals, though, are well formed and show all the interesting features that make tourmaline crystals so much fun to collect.
Uvite is a noted skarn mineral. The skarn is a term for a rock that is the product of a chemically unusual magma body that has intruded into and recrystallized a "dirty" limestone. The "dirty" limestone is not composed of just calcite, CaCO3, like "clean" limestone but is mixed with silicates and/or phosphates, etc. This mixing of the hot, chemically unusual liquids and volatiles of the magma with the different minerals of the "dirty" limestones produces some interesting and rare minerals after all the recrystallizing is done.