Crandallite is a phosphate mineral that often forms interesting botryoidal or crusty habit formations. It is commonly found as a secondary mineral in phosphate-rich environments and is frequently associated with wavellite or variscite.
Is this crandallite?
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 crandallite with a known reference. Crandallite sits at Mohs 5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Crandallite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Crandallite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: white, colorless, yellow, gray, brown.
- 5Look at form & habitCrystal system: trigonal. Typical habit: massive, botryoidal, spherical crusts, fibrous aggregates.
Often confused with
Crandallite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside crandallite
Minerals reported to co-occur with crandallite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- CaAl₃(PO₄)₂(OH)₅·H₂O
- Mohs hardness
- 5
- Density
- 2.7-2.9 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Trigonal
- Crystal habit
- Massive, Botryoidal, Spherical Crusts, Fibrous Aggregates
- Cleavage
- Perfect On {0001}
- Rarity
- Uncommon
- Uses
- Collector
- Host rock
- Phosphate-rich Sedimentary Deposits, Hydrothermal Veins, Weathered Igneous Rocks
- Typical price
- $10-50 for small specimens
Where rockhounds find crandallite
Classic worldwide localities
- USA
- Australia
- Germany
- France
Field-hunting tip
Look in phosphate-rich sedimentary deposits, hydrothermal veins, weathered igneous rocks country, the host setting where crandallite typically forms. If you start seeing wavellite, variscite, goethite in float, you are in the right ground. Field specimens usually show a massive, botryoidal, spherical crusts, fibrous aggregates habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify crandallite?+
Where is crandallite found?+
How much is crandallite worth?+
What rocks look like crandallite?+
What minerals are found with crandallite?+
What kind of rock does crandallite form in?+
What is crandallite used for?+
Find crandallite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
