Aurostibite is a rare gold-antimony mineral that typically forms as microscopic grains in gold-bearing quartz veins or as overgrowths on native gold. It is highly sought by mineral collectors specializing in gold species, often requiring microscopic study due to its occurrence as small, non-descript inclusions in massive ore samples.
Is this aurostibite?
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 aurostibite with a known reference. Aurostibite sits at Mohs 3 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Aurostibite leaves a black streak.
- 3Read the lusterHold the specimen under a strong light. Aurostibite typically shows a metallic luster.
- 4Match the color rangeCompare against the expected color range: white, pale yellow.
- 5Look at form & habitCrystal system: cubic. Typical habit: anhedral grains, massive, interstitial fillings.
Often confused with
Aurostibite vs. its common look-alikes — and how to tell them apart in the field.

How to tell apart: Pyrite is the harder of the two (Mohs 6-6.5 vs. 3); streak differs — Aurostibite leaves black, Pyrite leaves greenish-black to brownish-black.

How to tell apart: Aurostibite is noticeably harder (Mohs 3 vs. 2); streak differs — Aurostibite leaves black, Stibnite leaves lead-gray.

How to tell apart: Sperrylite is the harder of the two (Mohs 6-7 vs. 3).
Often found alongside aurostibite
Minerals reported to co-occur with aurostibite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- AuSb₂
- Mohs hardness
- 3
- Density
- 9.9-10.0 g/cm³
- Colors
- Streak
- Black
- Luster
- Metallic
- Transparency
- Opaque
- Crystal system
- Cubic
- Crystal habit
- Anhedral Grains, Massive, Interstitial Fillings
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Hydrothermal Gold Deposits
- Typical price
- $50-300 per small specimen
Where rockhounds find aurostibite
Classic worldwide localities
- Giant Yellowknife mine, Canada
- Fairview mine, South Africa
- Kalliojarvi, Finland
- Kuranakh deposit, Russia
Field-hunting tip
Look in hydrothermal gold deposits country — that is the host setting where aurostibite typically forms. If you start seeing gold, stibnite, arsenopyrite in float, you are in the right ground. Field specimens usually show a anhedral grains, massive, interstitial fillings habit, so train your eye for that shape before scanning the outcrop.



