Philipsburgite is a rare secondary copper arsenate mineral typically found as vibrant green crusts or small crystalline aggregates. It is prized by collectors for its brilliant color and is most famously associated with the Black Pine Mine in Montana, where it often coats other copper minerals.
Is this philipsburgite?
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 philipsburgite with a known reference. Philipsburgite sits at Mohs 2-3 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Philipsburgite leaves a pale green streak.
- 3Read the lusterHold the specimen under a strong light. Philipsburgite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: bright green, olive green, yellowish green.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: botryoidal crusts, aggregates, occasionally tiny prismatic crystals.
Often confused with
Philipsburgite vs. its common look-alikes — and how to tell them apart in the field.
How to tell apart: Austinite is the harder of the two (Mohs 4 vs. 2-3); streak differs — Philipsburgite leaves pale green, Austinite leaves white.
How to tell apart: Conichalcite is the harder of the two (Mohs 4.5 vs. 2-3); streak differs — Philipsburgite leaves pale green, Conichalcite leaves light green.
How to tell apart: Streak differs — Philipsburgite leaves pale green, Olivenite leaves olive-green; luster reads vitreous on Philipsburgite and adamantine on Olivenite.
Often found alongside philipsburgite
Minerals reported to co-occur with philipsburgite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- (Cu,Zn)₆(AsO₄,PO₄)₂(OH)₆·H₂O
- Mohs hardness
- 2-3
- Density
- 3.84 g/cm³
- Streak
- Pale Green
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Monoclinic
- Crystal habit
- Botryoidal Crusts, Aggregates, Occasionally Tiny Prismatic Crystals
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Oxidized Zones of Copper-arsenic Mineral Deposits
- Typical price
- $50-300 per specimen
Where rockhounds find philipsburgite
Classic worldwide localities
- Black Pine Mine, Montana, USA
- Tsumeb Mine, Namibia
- Majuba Hill Mine, Nevada, USA
Field-hunting tip
Look in oxidized zones of copper-arsenic mineral deposits country — that is the host setting where philipsburgite typically forms. If you start seeing aurichalcite, malachite, olivenite in float, you are in the right ground. Field specimens usually show a botryoidal crusts, aggregates, occasionally tiny prismatic crystals habit, so train your eye for that shape before scanning the outcrop.
Common questions
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Find philipsburgite on the map
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