Orthoserpierite is an extremely rare copper sulfate mineral that occurs as a secondary phase in the oxidation zones of ore deposits. It is structurally very similar to serpierite, forming delicate, sky-blue lath-like crystals or crusts that are highly prized by systematic mineral collectors.
Is this orthoserpierite?
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 orthoserpierite with a known reference. Orthoserpierite 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 green.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous.
- 4Match the color rangeCompare against the expected color range: pale blue green.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: crystalline, platy.
Often confused with
Orthoserpierite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Serpierite is the harder of the two (Mohs 3.5-4 vs. 2); streak differs, so Orthoserpierite leaves pale green, Serpierite leaves greenish white.
How to tell apart: Streak differs, so Orthoserpierite leaves pale green, Langite leaves greenish blue.
Often found alongside orthoserpierite
Minerals reported to co-occur with orthoserpierite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- CaCu₄(SO₄)₂(OH)₆·3H₂O
- Mohs hardness
- 2
- Density
- 3.00 g/cm³
- Colors
- Pale blue green
- Streak
- Pale green
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Orthorhombic
- Crystal habit
- Crystalline, platy
- Cleavage
- Perfect
- Fluorescence
- Mauve under SW and LW UV
- Rarity
- Rare
- Uses
- Collector
- Host rock
- A rare secondary mineral formed in the dump from a hydrothermal copper mine (Chessy, France)
Where rockhounds find orthoserpierite
Classic worldwide localities
- Childs-Aldwinkle mine, Copper Creek district, Pinal Co., Arizona, and at Sterling Hill, Ogdensburg, Sussex Co., New Jersey, USA
- Chessy, near Lyon, Rhône, France
- Tynagh mine, near Loughrea, Co. Galway, Ireland
- Vezzani, Corsica, France
- Glücksrad mine, near Oberschulenberg, Harz Mountains, Germany
Field-hunting tip
Where it forms: A rare secondary mineral formed in the dump from a hydrothermal copper mine (Chessy, France). If you start seeing devilline, gypsum, calcite in float, you are in the right ground. Typical habit: crystalline, platy. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify orthoserpierite?+
Where is orthoserpierite found?+
Is orthoserpierite safe to handle?+
What rocks look like orthoserpierite?+
What minerals are found with orthoserpierite?+
What kind of rock does orthoserpierite form in?+
What is orthoserpierite used for?+
Find orthoserpierite on the map
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