Irinarassite is a very rare tin-bearing garnet species discovered in the Wiluy River basin of Russia. It typically occurs as small dodecahedral crystals within skarn deposits and is highly prized by advanced mineral collectors for its unique composition.
Is this irinarassite?
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 irinarassite with a known reference. Irinarassite sits at Mohs 6-7 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Irinarassite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Irinarassite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: yellow, brown.
- 5Look at form & habitCrystal system: cubic. Typical habit: dodecahedral crystals.
Often confused with
Irinarassite vs. its common look-alikes — and how to tell them apart in the field.
Often found alongside irinarassite
Minerals reported to co-occur with irinarassite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Ca₃Sn₂Si₃O₁₂
- Mohs hardness
- 6-7
- Density
- 3.8-3.9 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Cubic
- Crystal habit
- Dodecahedral Crystals
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Skarn
- Typical price
- $50-500 thumbnail
Where rockhounds find irinarassite
Classic worldwide localities
- Sakha Republic, Russia
Field-hunting tip
Look in skarn country — that is the host setting where irinarassite typically forms. If you start seeing wollastonite, vesuvianite, calcite in float, you are in the right ground. Field specimens usually show a dodecahedral crystals habit, so train your eye for that shape before scanning the outcrop.





