Kingite is a rare hydrous aluminum phosphate mineral that typically forms white, chalky or porcellanous crusts in weathered phosphate deposits. It is a secondary mineral often found as an alteration product of other aluminum phosphates like wavellite. Collectors usually identify it by its distinct massive, dull appearance and its association with other phosphate minerals in secondary weathering zones.
Is this kingite?
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 kingite with a known reference. Kingite sits at Mohs 2 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Kingite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Kingite typically shows a dull luster.
- 4Match the color rangeCompare against the expected color range: white.
- 5Look at form & habitCrystal system: triclinic. Typical habit: porcellanous masses, coatings, or crusts.
Often confused with
Kingite vs. its common look-alikes — and how to tell them apart in the field.

How to tell apart: Wavellite is the harder of the two (Mohs 3.5-4 vs. 2); luster reads dull on Kingite and vitreous on Wavellite.

How to tell apart: Variscite is the harder of the two (Mohs 3.5-4.5 vs. 2); luster reads dull on Kingite and waxy on Variscite.

How to tell apart: Crandallite is the harder of the two (Mohs 5 vs. 2); luster reads dull on Kingite and vitreous on Crandallite.
Often found alongside kingite
Minerals reported to co-occur with kingite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Al₃(PO₄)₂(OH)₃·9H₂O
- Mohs hardness
- 2
- Density
- 2.21 g/cm³
- Colors
- Streak
- White
- Luster
- Dull
- Transparency
- Opaque
- Crystal system
- Triclinic
- Crystal habit
- Porcellanous Masses, Coatings, Or Crusts
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Phosphate-rich Sedimentary or Weathered Rocks
- Typical price
- $20-100 per specimen
Where rockhounds find kingite
Classic worldwide localities
- Iron Monarch Quarry, Iron Knob, South Australia
- Santa Rita, New Mexico, USA
Field-hunting tip
Look in phosphate-rich sedimentary or weathered rocks country — that is the host setting where kingite typically forms. If you start seeing wavellite, variscite, strengite in float, you are in the right ground. Field specimens usually show a porcellanous masses, coatings, or crusts habit, so train your eye for that shape before scanning the outcrop.

