Kapundaite is an extremely rare phosphate mineral that typically forms as small, bright yellow to orange-yellow radiating blades. It is primarily found as a secondary mineral in the oxidized zones of copper deposits, often occurring on limonite-rich matrices.
Is this kapundaite?
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 kapundaite with a known reference. Kapundaite 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. Kapundaite leaves a yellow streak.
- 3Read the lusterHold the specimen under a strong light. Kapundaite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: yellow, yellow-orange.
- 5Look at form & habitCrystal system: triclinic. Typical habit: bladed to lath-like crystals, often in radial sprays or crusts.
Often confused with
Kapundaite vs. its common look-alikes — and how to tell them apart in the field.
Often found alongside kapundaite
Minerals reported to co-occur with kapundaite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- (Na,Ca)₂(Fe³⁺,Mg)₄(PO₄)₄(OH)₂·5H₂O
- Mohs hardness
- 3
- Density
- 3.31 g/cm³
- Colors
- Streak
- Yellow
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Triclinic
- Crystal habit
- Bladed to Lath-like Crystals, Often in Radial Sprays or Crusts
- Cleavage
- Perfect On {010}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Oxidized Zones of Copper Ore Deposits
- Typical price
- $50-300 per specimen
Where rockhounds find kapundaite
Classic worldwide localities
- Kapunda Copper Mine, South Australia
- Brumado, Bahia, Brazil
Field-hunting tip
Look in oxidized zones of copper ore deposits country — that is the host setting where kapundaite typically forms. If you start seeing chalcosiderite, goethite, libethenite in float, you are in the right ground. Field specimens usually show a bladed to lath-like crystals, often in radial sprays or crusts habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify kapundaite?+
Where is kapundaite found?+
How much is kapundaite worth?+
What rocks look like kapundaite?+
What minerals are found with kapundaite?+
What kind of rock does kapundaite form in?+
What is kapundaite used for?+
Find kapundaite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
