Otavite is a rare mineral from the famous mines of
Otavi (hence the name), Namibia.
It is one of only a few cadmium minerals as cadmium is usually a trace element in other minerals.
Other cadmium minerals include:
the oxide mineral
the sulfide minerals
the sulfate mineral
and the arsenate minerals
All are rare minerals, as is otavite.
Otavite is a member of the
Calcite Group of minerals.
Most other members of this group are quite common and include such well known minerals as
Color is usually white, but can also be yellowish brown, reddish brown and brown.
Luster is adamantine to pearly.
Transparency crystals are usually translucent to transparent.
Crystal System is trigonal; bar 3 2/m.
Crystal Habits are limited to crusts and tiny scalahedral crystals.
Cleavage is perfect in 3 non-perpendicular directions forming rhombs.
Fracture is conchoidal.
Hardness is 3.5 - 4.
Specific Gravity is 5 (very heavy for a translucent mineral).
Streak is white.
Other Characteristics: Effervesces with acid and some specimens have fluoresced red under shortwave UV light.