Spertiniite is a rare copper hydroxide mineral that typically occurs as small, delicate blue to blue-green platy crystals. It is primarily found as a late-stage secondary mineral in cavities of alkaline igneous rocks, most notably at the Mont Saint-Hilaire locality in Canada.
Is this spertiniite?
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 spertiniite with a known reference. Spertiniite 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. Spertiniite leaves a pale blue streak.
- 3Read the lusterHold the specimen under a strong light. Spertiniite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: blue, blue-green.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: platy crystals, crusts.
Often confused with
Spertiniite vs. its common look-alikes — and how to tell them apart in the field.
How to tell apart: Azurite is the harder of the two (Mohs 3.5-4 vs. 2); streak differs — Spertiniite leaves pale blue, Azurite leaves light blue; luster reads vitreous on Spertiniite and vitreous to dull on Azurite.
How to tell apart: Malachite is the harder of the two (Mohs 3.5-4 vs. 2); streak differs — Spertiniite leaves pale blue, Malachite leaves light green.
Often found alongside spertiniite
Minerals reported to co-occur with spertiniite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Cu(OH)₂
- Mohs hardness
- 2
- Density
- 2.9 g/cm³
- Colors
- Streak
- Pale Blue
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Orthorhombic
- Crystal habit
- Platy Crystals, Crusts
- Cleavage
- Perfect On {001}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Alkaline Igneous Complexes
- Typical price
- $50-300+ for micro-mounts and thumbnail specimens
Where rockhounds find spertiniite
Classic worldwide localities
- Poudrette quarry, Mont Saint-Hilaire, Quebec, Canada
Field-hunting tip
Look in alkaline igneous complexes country — that is the host setting where spertiniite typically forms. If you start seeing dawsonite, analcime, calcite in float, you are in the right ground. Field specimens usually show a platy crystals, crusts habit, so train your eye for that shape before scanning the outcrop.
Common questions
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Find spertiniite on the map
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