Luetheite is a rare copper-aluminum arsenate mineral typically found as tiny, sky-blue to greenish-blue platy crystals. It is most famous from the Hilltop Mine in Arizona, where it occurs as a secondary mineral in oxidized ore zones. Collectors value it for its vivid color and association with other rare copper secondary species.
Is this luetheite?
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 luetheite with a known reference. Luetheite 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: white.
- 3Read the lusterHold the specimen under a strong light. Luster: pearly.
- 4Match the color rangeCompare against the expected color range: blue, greenish, light green.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: platy crystals, crusts.
Often confused with
Luetheite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside luetheite
Minerals reported to co-occur with luetheite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- CuAl(AsO₄)(OH)₂
- Mohs hardness
- 3
- Density
- 4.28 g/cm³
- Colors
- Streak
- White
- Luster
- Pearly
- Transparency
- Semitransparent
- Crystal system
- Monoclinic
- Crystal habit
- Platy crystals, crusts
- Cleavage
- On {100}, fair to good
- Rarity
- Rare
- Uses
- Collector
- Host rock
- A rare mineral filling cavities in intensely altered volcanic rock (Patagonia district, Arizona, USA); in the oxidized zone of a copper deposit (Majuba Hill, Nevada, USA)
Where rockhounds find luetheite
Classic worldwide localities
- A prospect about 2.7 km southeast of the Flux mine, Patagonia district, Santa Cruz Co., Arizona, USA
- Majuba Hill mine, Antelope district, Pershing Co., Nevada, USA
- Bali Lo copper prospect, 11 km west-southwest of Ashburton Downs homestead, Capricorn Range, Western Australia
Field-hunting tip
Where it forms: A rare mineral filling cavities in intensely altered volcanic rock (Patagonia district, Arizona, USA); in the oxidized zone of a copper deposit (Majuba Hill, Nevada, USA). If you start seeing chenevixite, cornubite, pharmacosiderite in float, you are in the right ground. Typical habit: platy crystals, crusts. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify luetheite?+
Where is luetheite found?+
Is luetheite safe to handle?+
What rocks look like luetheite?+
What minerals are found with luetheite?+
What kind of rock does luetheite form in?+
What is luetheite used for?+
Find luetheite on the map
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