Miersite is a rare silver copper iodide mineral that typically occurs as small, bright yellow tetrahedral crystals. It is primarily found in the oxidized zones of silver ore deposits where it is often associated with other halide minerals. Collectors value it for its distinct bright yellow color and relatively rare occurrence.
Is this miersite?
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 miersite with a known reference. Miersite sits at Mohs 2.5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: canary-yellow.
- 3Read the lusterHold the specimen under a strong light. Luster: adamantine.
- 4Match the color rangeCompare against the expected color range: greenish, canary yellow, light yellow.
- 5Look at form & habitCrystal system: cubic. Typical habit: encrustations.
Often confused with
Miersite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Miersite is noticeably harder (Mohs 2.5 vs. 1.5); streak differs, so Miersite leaves canary-yellow, Iodargyrite leaves yellow, shining; luster reads adamantine on Miersite and resinous to adamantine, pearly on cleavage surfaces on Iodargyrite.
How to tell apart: Streak differs, so Miersite leaves canary-yellow, Bromargyrite leaves white to yellowish white; luster reads adamantine on Miersite and resinous to adamantine, waxy on Bromargyrite.
Often found alongside miersite
Minerals reported to co-occur with miersite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- AgI
- Mohs hardness
- 2.5
- Density
- 5.64 g/cm³
- Streak
- Canary-yellow
- Luster
- Adamantine
- Transparency
- Transparent
- Crystal system
- Cubic
- Crystal habit
- Encrustations
- Cleavage
- {011}, perfect
- Rarity
- Rare
- Uses
- Collector
- Host rock
- A rare mineral in the oxidized zone of some Pb–Zn–Cu–Ag deposits, especially in arid regions
Where rockhounds find miersite
Classic worldwide localities
- Contention mine and Joe shaft, Tombstone, USA
- Southwest mine, Bisbee, Cochise Co., USA
- Mildren and Steppe claim, South Comobabi Mountains, Pima Co., Arizona, USA
- Broken Hill, New South Wales, Australia
- Likasi mine, Katanga Province, Congo (Shaba Province, Zaire)
Field-hunting tip
Where it forms: A rare mineral in the oxidized zone of some Pb–Zn–Cu–Ag deposits, especially in arid regions. If you start seeing iodargyrite, chlorargyrite, malachite in float, you are in the right ground. Typical habit: encrustations. Train your eye for that shape before scanning the outcrop.
Common questions
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Find miersite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
