Kolbeckite is a rare scandium phosphate mineral often appearing as small, transparent apple-green crystals. It is highly sought after by collectors due to its status as a primary scandium-bearing mineral and its rarity in the field. It is most commonly found in association with hydrothermal vein deposits, particularly those containing tin and tungsten.
Is this kolbeckite?
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 kolbeckite with a known reference. Kolbeckite sits at Mohs 3-5, 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 to pearly.
- 4Match the color rangeCompare against the expected color range: blue gray, colorless, greenish white, yellowish, light blue.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: spherical.
Often confused with
Kolbeckite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside kolbeckite
Minerals reported to co-occur with kolbeckite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- ScPO₄·2H₂O
- Mohs hardness
- 3-5
- Density
- 2.36 g/cm³
- Streak
- White
- Luster
- Vitreous to pearly
- Transparency
- Transparent
- Crystal system
- Monoclinic
- Crystal habit
- Spherical
- Cleavage
- On {010}, distinct; on {100} and {001}, poor
- Rarity
- Rare
- Uses
- Collector
- Host rock
- A very rare secondary mineral in some hydrothermal metallic veins and phosphate deposits
Where rockhounds find kolbeckite
Classic worldwide localities
- Little Green Monster mine, Clay Canyon, about nine km west of Fairfield, Utah Co., USA
- Wilson Springs (Potash Sulphur Springs) mine, Garland Co., and as Christy Pit, Magnet Cove, Hot Spring Co., Arkansas, USA
- Flambeau mine, southwest of Ladysmith, Rusk Co., Wisconsin, USA
- Sadisdorf copper mine, near Schmiedeberg, Saxony, Germany
- Baia Sprie (Felsőbánya), Romania
- Schlarbaum quarry, near Gleichenberg, Styria, Austria
Field-hunting tip
Where it forms: A very rare secondary mineral in some hydrothermal metallic veins and phosphate deposits. If you start seeing chlorite, quartz, miargyrite in float, you are in the right ground. Typical habit: spherical. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify kolbeckite?+
Where is kolbeckite found?+
What rocks look like kolbeckite?+
What minerals are found with kolbeckite?+
What kind of rock does kolbeckite form in?+
What is kolbeckite used for?+
Find kolbeckite on the map
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