Rickardite is a rare copper telluride mineral known for its distinctive and vibrant purplish-red color when freshly broken, though it quickly tarnishes to a darker color upon exposure to air. It is typically found in massive forms within hydrothermal veins associated with other telluride minerals.
Is this rickardite?
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 rickardite with a known reference. Rickardite 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: black.
- 3Read the lusterHold the specimen under a strong light. Luster: metallic.
- 4Match the color rangeCompare against the expected color range: violet, purple red.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: massive.
Often confused with
Rickardite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Rickardite is noticeably harder (Mohs 3.5 vs. 1-2).
How to tell apart: Rickardite is noticeably harder (Mohs 3.5 vs. 2.7); streak differs, so Rickardite leaves black, Berzelianite leaves shining.
How to tell apart: Streak differs, so Rickardite leaves black, Bornite leaves pale grayish black.
Often found alongside rickardite
Minerals reported to co-occur with rickardite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Cu₄₋ₓTe₂
- Mohs hardness
- 3.5
- Density
- 7.54 g/cm³
- Colors
- Streak
- Black
- Luster
- Metallic
- Transparency
- Opaque
- Crystal system
- Orthorhombic
- Crystal habit
- Massive
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- A late-stage mineral of low-temperature hydrothermal origin in some Te-bearing mineral deposits
Where rockhounds find rickardite
Classic worldwide localities
- Good Hope mine, Vulcan, Gunnison Co. (type locality), Colorado, USA
- Empress Josephine mine, Bonanza district, Saguache Co., at Buckeye Gulch, Lake Co., Colorado, USA
- Junction and Campbell mines, Bisbee, and the Little Joe shaft, Tombstone, Cochise Co., Arizona, USA
- Horne mine, Noranda, Quebec, Canada
- San Miguel prospect, 10 km southwest of Moctezuma, Sonora, Mexico
- Lomo Hierro silver deposit, western Cuba
Field-hunting tip
Where it forms: A late-stage mineral of low-temperature hydrothermal origin in some Te-bearing mineral deposits. If you start seeing vulcanite, tellurium, cameronite in float, you are in the right ground. Typical habit: massive. Train your eye for that shape before scanning the outcrop.
Common questions
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Find rickardite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
