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. Streak: pale blue.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous.
- 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).
How to tell apart: Malachite is the harder of the two (Mohs 3.5-4 vs. 2); luster reads vitreous on Spertiniite and adamantine to vitreous; silky if fibrous; dull to earthy if massive on Malachite.
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
- 3.93 g/cm³
- Colors
- Streak
- Pale blue
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Orthorhombic
- Crystal habit
- Platy crystals, crusts
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- A very rare mineral, altering from chalcocite in alkaline groundwater, in a rodingite dike near the contact with a serpentinized dunite (Jeffrey mine, Quebec, Canada)
Where rockhounds find spertiniite
Classic worldwide localities
- Ely, White Pine Co., Nevada, and from Bisbee, Cochise Co., Arizona, USA
- Jeffrey mine, Asbestos, and at Mont Saint-Hilaire, Quebec, Canada
- Dzhezkazgan, Kazakhstan
- Juliüshutte, Astfeld, Harz Mountains, in slag, Germany
- Tsumeb, Namibia
Field-hunting tip
Where it forms: A very rare mineral, altering from chalcocite in alkaline groundwater, in a rodingite dike near the contact with a serpentinized dunite (Jeffrey mine, Quebec, Canada). If you start seeing chalcocite, atacamite, copper in float, you are in the right ground. Typical habit: platy crystals, crusts. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify spertiniite?+
Where is spertiniite found?+
Is spertiniite safe to handle?+
What rocks look like spertiniite?+
What minerals are found with spertiniite?+
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Find spertiniite on the map
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