Sorosite is an extremely rare copper-tin alloy mineral found primarily as tiny grains in alluvial deposits. It is identifiable by its bright metallic luster and silver-white appearance, often requiring analytical testing for positive identification due to its similarity to other tin-bearing minerals.
Is this sorosite?
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 sorosite with a known reference. Sorosite sits at Mohs 3.5-4 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Sorosite leaves a silver-white streak.
- 3Read the lusterHold the specimen under a strong light. Sorosite typically shows a metallic luster.
- 4Match the color rangeCompare against the expected color range: silver-white, tin-white.
- 5Look at form & habitCrystal system: hexagonal. Typical habit: massive, anhedral grains.
Often confused with
Sorosite vs. its common look-alikes — and how to tell them apart in the field.
How to tell apart: Streak differs — Sorosite leaves silver-white, Stannite leaves black.
How to tell apart: Sorosite is noticeably harder (Mohs 3.5-4 vs. 1.5); streak differs — Sorosite leaves silver-white, Native Tin leaves white.
Often found alongside sorosite
Minerals reported to co-occur with sorosite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Cu₁₊ₓSn
- Mohs hardness
- 3.5-4
- Density
- 8.8-9.0 g/cm³
- Colors
- Streak
- Silver-white
- Luster
- Metallic
- Transparency
- Opaque
- Crystal system
- Hexagonal
- Crystal habit
- Massive, Anhedral Grains
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Placer Deposits, Alluvial Gravels
- Typical price
- $50-300 per specimen
Where rockhounds find sorosite
Classic worldwide localities
- Russia
- United States
Field-hunting tip
Look in placer deposits, alluvial gravels country — that is the host setting where sorosite typically forms. If you start seeing cassiterite, stannite, native tin in float, you are in the right ground. Field specimens usually show a massive, anhedral grains habit, so train your eye for that shape before scanning the outcrop.
Common questions
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Find sorosite on the map
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