Magnesiocoulsonite is a rare member of the spinel group characterized by its magnesium-vanadium composition. It typically occurs as small, dark, metallic octahedral grains found within metamorphic or ultramafic geological environments.
Is this magnesiocoulsonite?
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 magnesiocoulsonite with a known reference. Magnesiocoulsonite sits at Mohs 5.5-6.5 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Magnesiocoulsonite leaves a black streak.
- 3Read the lusterHold the specimen under a strong light. Magnesiocoulsonite typically shows a metallic luster.
- 4Match the color rangeCompare against the expected color range: black.
- 5Look at form & habitCrystal system: cubic. Typical habit: octahedral crystals, massive.
Often confused with
Magnesiocoulsonite vs. its common look-alikes — and how to tell them apart in the field.
How to tell apart: Luster reads metallic on Magnesiocoulsonite and submetallic on Coulsonite.
How to tell apart: Streak differs — Magnesiocoulsonite leaves black, Chromite leaves dark brown; luster reads metallic on Magnesiocoulsonite and submetallic on Chromite.
Often found alongside magnesiocoulsonite
Minerals reported to co-occur with magnesiocoulsonite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- MgV₂O₄
- Mohs hardness
- 5.5-6.5
- Density
- 4.5-4.8 g/cm³
- Colors
- Streak
- Black
- Luster
- Metallic
- Transparency
- Opaque
- Crystal system
- Cubic
- Crystal habit
- Octahedral Crystals, Massive
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Ultramafic Rocks, Metamorphosed Vanadium-rich Sediments
- Typical price
- $50-300 per specimen
Where rockhounds find magnesiocoulsonite
Classic worldwide localities
- Kola Peninsula, Russia
- Sulu Archipelago, Philippines
- Aosta Valley, Italy
Field-hunting tip
Look in ultramafic rocks, metamorphosed vanadium-rich sediments country — that is the host setting where magnesiocoulsonite typically forms. If you start seeing magnetite, diopside, chlorite in float, you are in the right ground. Field specimens usually show a octahedral crystals, massive habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify magnesiocoulsonite?+
Where is magnesiocoulsonite found?+
How much is magnesiocoulsonite worth?+
What rocks look like magnesiocoulsonite?+
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Find magnesiocoulsonite on the map
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