Mariinskite is an extremely rare beryllium-chromium oxide mineral discovered in the Mariinskoye emerald deposit of the Ural Mountains. It is structurally related to chrysoberyl and is prized by advanced collectors for its intense green color and unique chemical composition. Due to its scarcity and typical microscopic grain size, it is almost exclusively found in scientific research collections or held by specialized mineral curators.
Is this mariinskite?
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 mariinskite with a known reference. Mariinskite sits at Mohs 8.5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: pale green.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous.
- 4Match the color rangeCompare against the expected color range: dark green.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: anhedral grains.
Often confused with
Mariinskite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Mariinskite leaves pale green, Chrysoberyl leaves white.
How to tell apart: Streak differs, so Mariinskite leaves pale green, Alexandrite leaves white.
How to tell apart: Mariinskite is noticeably harder (Mohs 8.5 vs. 6.5-7); streak differs, so Mariinskite leaves pale green, Uvarovite leaves white.
Often found alongside mariinskite
Minerals reported to co-occur with mariinskite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- BeCr₂O₄
- Mohs hardness
- 8.5
- Density
- 4.25 g/cm³
- Colors
- Streak
- Pale green
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Orthorhombic
- Crystal habit
- Anhedral grains
- Rarity
- Rare
- Uses
- Collector, Scientific research
- Host rock
- Replacing low-Al chromite of chromitite lens in serpentinite, probably of metasomatic origin
Where rockhounds find mariinskite
Classic worldwide localities
- Mariinskoye (Malyshevskoe) Be deposit, Ural Emerald Mines, Middle Urals, Russia
Field-hunting tip
Where it forms: Replacing low-Al chromite of chromitite lens in serpentinite, probably of metasomatic origin. If you start seeing fluorophlogopite, eskolaite, dravite-fluordravite in float, you are in the right ground. Typical habit: anhedral grains. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify mariinskite?+
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What rocks look like mariinskite?+
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Find mariinskite on the map
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