Cuprokalininite is a rare copper-chromium sulfide belonging to the spinel group. It typically appears as opaque, metallic black octahedral crystals found in association with hydrothermal sulfide ore bodies.
Is this cuprokalininite?
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 cuprokalininite with a known reference. Cuprokalininite sits at Mohs 4.5-5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: black.
- 3Read the lusterHold the specimen under a strong light. Luster: submetallic.
- 4Match the color rangeCompare against the expected color range: black with dark-bronze tint.
- 5Look at form & habitCrystal system: cubic. Typical habit: octahedral crystals, massive.
Often confused with
Cuprokalininite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Luster reads submetallic on Cuprokalininite and metallic to submetallic, may be dull on Magnetite.
How to tell apart: Streak differs, so Cuprokalininite leaves black, Chromite leaves brown; luster reads submetallic on Cuprokalininite and metallic to submetallic on Chromite.
Often found alongside cuprokalininite
Minerals reported to co-occur with cuprokalininite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- CuCr₂S₄
- Mohs hardness
- 4.5-5
- Density
- 4.16 g/cm³
- Colors
- Black with dark-bronze tint
- Streak
- Black
- Luster
- Submetallic
- Transparency
- Opaque
- Crystal system
- Cubic
- Crystal habit
- Octahedral crystals, massive
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- As disseminated inclusions in quartz from Cr-V-bearing quartz-diopside granulite facies metamorphic rocks
Where rockhounds find cuprokalininite
Classic worldwide localities
- Sludyanka complex, South Baikal region, Russia
Field-hunting tip
Where it forms: As disseminated inclusions in quartz from Cr-V-bearing quartz-diopside granulite facies metamorphic rocks. If you start seeing cr-v-tremolite and mica, calcite, cr-v spinels in float, you are in the right ground. Typical habit: octahedral crystals, massive. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify cuprokalininite?+
Where is cuprokalininite found?+
Is cuprokalininite safe to handle?+
What rocks look like cuprokalininite?+
What minerals are found with cuprokalininite?+
What kind of rock does cuprokalininite form in?+
What is cuprokalininite used for?+
Find cuprokalininite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
