Oxy-chromium-dravite is a rare member of the tourmaline group, distinguished by its intense green color derived from chromium substitution. It typically occurs as prismatic crystals within metamorphic rocks and is highly prized by collectors for its unique chemistry and vivid, saturated hues.
Is this oxy-chromium-dravite?
5-step field checkRun through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.
- 1Test the hardnessTry to scratch oxy-chromium-dravite with a known reference. Oxy-chromium-dravite sits at Mohs 7.5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: green.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous.
- 4Match the color rangeCompare against the expected color range: emerald-green.
- 5Look at form & habitCrystal system: trigonal. Typical habit: prismatic crystals.
Often confused with
Oxy-chromium-dravite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside oxy-chromium-dravite
Minerals reported to co-occur with oxy-chromium-dravite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- NaCr₃(Cr₄Mg₂)(Si₆O₁₈)(BO₃)₃(OH)₃O
- Mohs hardness
- 7.5
- Density
- 3.32 g/cm³
- Colors
- Streak
- Green
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Trigonal
- Crystal habit
- Prismatic crystals
- Cleavage
- Indistinct
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In Cr-V-bearing calcite-quartz-diopside metamorphic rocks (granulite facies)
Where rockhounds find oxy-chromium-dravite
Classic worldwide localities
- Pereval marble quarry, near Sludyanka, Irkutsk region, Southern Lake Baikal, Russia
Field-hunting tip
Where it forms: In Cr-V-bearing calcite-quartz-diopside metamorphic rocks (granulite facies). If you start seeing quartz, calcite, chromphyllite in float, you are in the right ground. Typical habit: prismatic crystals. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify oxy-chromium-dravite?+
Where is oxy-chromium-dravite found?+
What rocks look like oxy-chromium-dravite?+
What minerals are found with oxy-chromium-dravite?+
What kind of rock does oxy-chromium-dravite form in?+
What is oxy-chromium-dravite used for?+
Find oxy-chromium-dravite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
