Roquesite is a rare copper indium sulfide mineral that typically occurs as microscopic grains within other sulfide minerals like chalcopyrite. It is found in hydrothermal polymetallic deposits where indium enrichment has occurred, making it a significant mineral for geological study rather than large-scale aesthetic collection.
Is this roquesite?
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 roquesite with a known reference. Roquesite 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. Roquesite leaves a black streak.
- 3Read the lusterHold the specimen under a strong light. Roquesite typically shows a metallic luster.
- 4Match the color rangeCompare against the expected color range: grayish-black, dark gray.
- 5Look at form & habitCrystal system: tetragonal. Typical habit: massive, anhedral grains.
Often confused with
Roquesite vs. its common look-alikes — and how to tell them apart in the field.
How to tell apart: Streak differs — Roquesite leaves black, Chalcopyrite leaves greenish-black.
How to tell apart: Streak differs — Roquesite leaves black, Sphalerite leaves white to yellow-brown; luster reads metallic on Roquesite and resinous to submetallic on Sphalerite.
Often found alongside roquesite
Minerals reported to co-occur with roquesite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- CuInS₂
- Mohs hardness
- 3.5-4
- Density
- 5.65 g/cm³
- Colors
- Streak
- Black
- Luster
- Metallic
- Transparency
- Opaque
- Crystal system
- Tetragonal
- Crystal habit
- Massive, Anhedral Grains
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Hydrothermal Sulfide Veins
- Typical price
- $50-300 per specimen
Where rockhounds find roquesite
Classic worldwide localities
- Roques, France
- Toyoha mine, Japan
- Mount Pleasant, Canada
- Mercur, USA
Field-hunting tip
Look in hydrothermal sulfide veins country — that is the host setting where roquesite typically forms. If you start seeing chalcopyrite, sphalerite, cassiterite 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 roquesite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
