Augelite is a rare phosphate mineral often found as attractive, transparent, wedge-shaped crystals. It is highly prized by collectors for its clarity and aesthetic crystal habits, though it is typically found in small, localized deposits.
Is this augelite?
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 augelite with a known reference. Augelite sits at Mohs 4.5-5, 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: vitreous, pearly on perfect {110} cleavage.
- 4Match the color rangeCompare against the expected color range: colorless, yellow, yellow green, white, light blue.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: tabular to prismatic crystals, often wedge-shaped.
Often confused with
Augelite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside augelite
Minerals reported to co-occur with augelite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Al₂PO₄(OH)₃
- Mohs hardness
- 4.5-5
- Density
- 2.696 g/cm³
- Streak
- White
- Luster
- Vitreous, pearly on perfect {110} cleavage
- Transparency
- Transparent
- Crystal system
- Monoclinic
- Crystal habit
- Tabular to prismatic crystals, often wedge-shaped
- Cleavage
- {110}, perfect; {201}, good; {001} and {101}, imperfect
- Rarity
- Rare
- Uses
- Collector, Gemstone
- Host rock
- Formed by hydrogen metamorphism of phosphate-bearing rocks in peraluminous sediments; in some high-temperature hydrothermal ore deposits
Where rockhounds find augelite
Classic worldwide localities
- Champion mine, White Mountains, Mono Co., California, USA
- Palermo #1 mine, near North Groton, Grafton Co., and the G.E. Smith mine, Newport, Sullivan Co., New Hampshire, USA
- Hugo and Ingersoll mines, near Keystone, Pennington Co., South Dakota, USA
- White Picacho district, Maricopa and Yavapai Cos., Arizona, USA
- Västanå mine, near Näsum, Skåne, and at Hålsjöberg, Värmland, Sweden
- Mbale, Uganda
Field-hunting tip
Where it forms: Formed by hydrogen metamorphism of phosphate-bearing rocks in peraluminous sediments; in some high-temperature hydrothermal ore deposits. If you start seeing attakolite, svanbergite, lazulite in float, you are in the right ground. Typical habit: tabular to prismatic crystals, often wedge-shaped. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify augelite?+
Where is augelite found?+
What rocks look like augelite?+
What minerals are found with augelite?+
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What is augelite used for?+
Find augelite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
