Native indium is an extremely rare metallic mineral that typically occurs as tiny inclusions within other tin-bearing minerals. Because it is highly malleable and ductile, it is almost never found as well-formed macro-crystals, appearing instead as microscopic grains or small masses in specialized geological environments.
Is this native indium?
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 native indium with a known reference. Native Indium sits at Mohs 3.5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: white.
- 3Read the lusterHold the specimen under a strong light. Luster: metallic.
- 4Match the color rangeCompare against the expected color range: yellow gray.
- 5Look at form & habitCrystal system: tetragonal. Typical habit: irregular grains, inclusions, rarely microscopic crystals.
Often confused with
Native Indium vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Native Indium is noticeably harder (Mohs 3.5 vs. 2); streak differs, so Native Indium leaves white, Native Tin leaves gray white.
How to tell apart: Native Indium is noticeably harder (Mohs 3.5 vs. 1.5); streak differs, so Native Indium leaves white, Native Lead leaves lead-gray.
How to tell apart: Native Indium is noticeably harder (Mohs 3.5 vs. 2-2.5); streak differs, so Native Indium leaves white, Native Bismuth leaves pale silver.
Often found alongside native indium
Minerals reported to co-occur with native indium. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- In
- Mohs hardness
- 3.5
- Density
- 7.2-7.42 g/cm³
- Colors
- Streak
- White
- Luster
- Metallic
- Transparency
- Opaque
- Crystal system
- Tetragonal
- Crystal habit
- Irregular grains, inclusions, rarely microscopic crystals
- Cleavage
- Distinct on {001}
- Rarity
- Rare
- Uses
- Collector, Scientific research
- Host rock
- In greisenized and albitized granite (Orlovskoye deposit, Russia)
Where rockhounds find native indium
Classic worldwide localities
- Orlovskoye tantalum deposit, eastern Transbaikal (type locality), and an undefined locality in the Ukrainian Shield, Russia
Field-hunting tip
Where it forms: In greisenized and albitized granite (Orlovskoye deposit, Russia). If you start seeing silver in float, you are in the right ground. Typical habit: irregular grains, inclusions, rarely microscopic crystals. Train your eye for that shape before scanning the outcrop.
Common questions
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Find native indium on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
