THE MINERAL UVAROVITE
- Chemistry: Ca3Cr2(SiO4)3, Calcium Chromium Silicate
- Class: Silicates
- Subclass: Nesosilicates
- Group: Garnets
- Uses: Gemstones and mineral specimens
- See our natural Uvarovite Mineral Specimens
For Garnet Jewelry, see: GARNET JEWELRY
, like other garnets, forms rounded crystals with 12 rhombic or 24 trapezoidal faces or combinations of these and some other forms.
This crystal habit is classic for the garnet minerals.
Uvarovite is the only consistently green garnet and has a beautiful emerald-green color.
As with the other calcium garnets (andradite and grossular), uvarovite is formed from the metamorphism of impure siliceous limestones and some other rocks that contain chromium.
Mineral specimens of uvarovite are much sought after by collectors for outstanding brilliance and color.
- Color is a bright green.
- Luster is vitreous.
- Transparency crystals are transparent to translucent.
- Crystal System is isometric; 4/m bar 3 2/m
- Crystal Habits include the typical rhombic dodecahedron.
But more commonly is found as the 24 sided trapezohedron.
Combinations of these forms are common.
Massive and granular occurrences are also seen.
- Cleavage is absent.
- Fracture is conchoidal.
- Hardness is 6.5 - 7
- Specific Gravity is approximately 3.8 or less (above average for translucent minerals).
- Streak is white.
- Associated Minerals are chromite and serpentine.
- Other Characteristics: index of refraction is 1.86. dodecahedral faces may show striations.
- Notable Occurrences are Finland; Sarany, Ural Mountains Region, Russia; California and South Africa.
- Best Field Indicators are crystal habit, color, locality and hardness.