Petersite-(Ce) is a rare member of the mixite group that forms beautiful, needle-like acicular crystals or radial tufts. Collectors primarily seek it for its vibrant yellow to brownish-green pom-pom clusters found within oxidized copper ore zones.
Is this petersite-(ce)?
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 petersite-(ce) with a known reference. Petersite-(Ce) sits at Mohs 3-4 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Petersite-(Ce) leaves a yellowish white streak.
- 3Read the lusterHold the specimen under a strong light. Petersite-(Ce) typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: yellow, brown, greenish.
- 5Look at form & habitCrystal system: hexagonal. Typical habit: acicular clusters, fibrous tufts, spherical aggregates.
Often confused with
Petersite-(Ce) vs. its common look-alikes — and how to tell them apart in the field.
Often found alongside petersite-(ce)
Minerals reported to co-occur with petersite-(ce). Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- (Ce,Ca,La)Cu₆(PO₄)₃(OH)₆·3H₂O
- Mohs hardness
- 3-4
- Density
- 4.2 g/cm³
- Streak
- Yellowish White
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Hexagonal
- Crystal habit
- Acicular Clusters, Fibrous Tufts, Spherical Aggregates
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Oxidized Hydrothermal Copper Deposits
- Typical price
- $50-300 per specimen depending on size and crystal quality
Where rockhounds find petersite-(ce)
Classic worldwide localities
- Luobi, Hainan, China
- Piesky, Slovakia
- Majuba Hill, Nevada, USA
Field-hunting tip
Look in oxidized hydrothermal copper deposits country — that is the host setting where petersite-(ce) typically forms. If you start seeing malachite, azurite, quartz in float, you are in the right ground. Field specimens usually show a acicular clusters, fibrous tufts, spherical aggregates habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify petersite-(ce)?+
Where is petersite-(ce) found?+
How much is petersite-(ce) worth?+
Is petersite-(ce) safe to handle?+
What rocks look like petersite-(ce)?+
What minerals are found with petersite-(ce)?+
What kind of rock does petersite-(ce) form in?+
What is petersite-(ce) used for?+
Find petersite-(ce) on the map
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