Spencerite is a rare secondary zinc phosphate mineral typically found in the oxidized zones of zinc-rich ore deposits. It often forms distinctive pearly, platy crystals or foliated masses associated with other zinc minerals like smithsonite.
Is this spencerite?
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 spencerite with a known reference. Spencerite sits at Mohs 2.5 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Spencerite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Spencerite typically shows a pearly luster.
- 4Match the color rangeCompare against the expected color range: white, colorless, gray.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: platy crystals, tabular aggregates.
Often confused with
Spencerite vs. its common look-alikes — and how to tell them apart in the field.
How to tell apart: Hopeite is the harder of the two (Mohs 3.5 vs. 2.5); luster reads pearly on Spencerite and vitreous on Hopeite.
How to tell apart: Parahopeite is the harder of the two (Mohs 3.5 vs. 2.5); luster reads pearly on Spencerite and vitreous on Parahopeite.
Often found alongside spencerite
Minerals reported to co-occur with spencerite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Zn₄(PO₄)₂(OH)₂·3H₂O
- Mohs hardness
- 2.5
- Density
- 3.1 g/cm³
- Streak
- White
- Luster
- Pearly
- Transparency
- Translucent
- Crystal system
- Monoclinic
- Crystal habit
- Platy Crystals, Tabular Aggregates
- Cleavage
- Perfect On {010}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Oxidized Zinc Deposits
- Typical price
- $50-500 depending on specimen quality and size
Where rockhounds find spencerite
Classic worldwide localities
- Salmo, British Columbia, Canada
- Broken Hill, New South Wales, Australia
Field-hunting tip
Look in oxidized zinc deposits country — that is the host setting where spencerite typically forms. If you start seeing hopeite, smithsonite, hemimorphite in float, you are in the right ground. Field specimens usually show a platy crystals, tabular aggregates habit, so train your eye for that shape before scanning the outcrop.
Common questions
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Find spencerite on the map
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