Hemihedrite is a rare lead zinc chromate-silicate mineral prized by collectors for its vivid orange-red color and adamantine luster. It typically forms tabular, blocky crystals within oxidized zones of hydrothermal base metal deposits, often associated with other rare secondary lead minerals.
Is this hemihedrite?
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 hemihedrite with a known reference. Hemihedrite 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. Streak: saffron-yellow.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous.
- 4Match the color rangeCompare against the expected color range: orange, brown, black.
- 5Look at form & habitCrystal system: triclinic. Typical habit: tabular crystals, blocky, sometimes as crusts.
Often confused with
Hemihedrite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Hemihedrite leaves saffron-yellow, Wulfenite leaves white; luster reads vitreous on Hemihedrite and resinous, subadamantine to adamantine on Wulfenite.
How to tell apart: Streak differs, so Hemihedrite leaves saffron-yellow, Crocoite leaves yellow-orange; luster reads vitreous on Hemihedrite and adamantine on Crocoite.
How to tell apart: Streak differs, so Hemihedrite leaves saffron-yellow, Phoenicochroite leaves brick-red to yellowish orange; luster reads vitreous on Hemihedrite and adamantine to resinous, glistening on Phoenicochroite.
Often found alongside hemihedrite
Minerals reported to co-occur with hemihedrite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Pb₁₀Zn(CrO₄)₆(SiO₄)₂(OH)₂
- Mohs hardness
- 3
- Density
- 6.42 g/cm³
- Streak
- Saffron-yellow
- Luster
- Vitreous
- Transparency
- Translucent to transparent
- Crystal system
- Triclinic
- Crystal habit
- Tabular crystals, blocky, sometimes as crusts
- Cleavage
- Distinct
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Formed through oxidation of galena, sphalerite, and pyrite, in the oxide zone of hydrothermal lead-bearing veins
Where rockhounds find hemihedrite
Classic worldwide localities
- Florence Lead-Silver mine, Tortilla Mountains, Pinal Co., and the Pack Rat claim, the Moon Anchor mine, and the Potter-Cramer property, Belmont Mountains, Maricopa Co., Arizona, USA
- Boulder City, Clark Co., Nevada, USA
- Seh-Changi mine, near Neyband, Khorassan, Iran
Field-hunting tip
Where it forms: Formed through oxidation of galena, sphalerite, and pyrite, in the oxide zone of hydrothermal lead-bearing veins. If you start seeing cerussite, phoenicochroite, vauquelinite in float, you are in the right ground. Typical habit: tabular crystals, blocky, sometimes as crusts. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify hemihedrite?+
Where is hemihedrite found?+
Is hemihedrite safe to handle?+
What rocks look like hemihedrite?+
What minerals are found with hemihedrite?+
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Find hemihedrite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
