Paratacamite-(Mg) is a rare copper hydroxychloride mineral typically found as a secondary mineral in oxidized zones of copper-rich hydrothermal deposits. It often appears as small, deep green rhombohedral crystals or as earthy coatings on other minerals like atacamite.
Is this paratacamite-(mg)?
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 paratacamite-(mg) with a known reference. Paratacamite-(Mg) sits at Mohs 3-3.5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: light green.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous.
- 4Match the color rangeCompare against the expected color range: medium, dark green.
- 5Look at form & habitCrystal system: trigonal. Typical habit: rhombohedral crystals, crusts, massive.
Often confused with
Paratacamite-(Mg) vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Paratacamite-(Mg) leaves light green, Atacamite leaves apple-green; luster reads vitreous on Paratacamite-(Mg) and adamantine to vitreous on Atacamite.
How to tell apart: Streak differs, so Paratacamite-(Mg) leaves light green, Clinoatacamite leaves greenish white; luster reads vitreous on Paratacamite-(Mg) and adamantine to vitreous on Clinoatacamite.
Often found alongside paratacamite-(mg)
Minerals reported to co-occur with paratacamite-(mg). Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Cu₃Mg(OH)₆Cl₂
- Mohs hardness
- 3-3.5
- Density
- 3.50 g/cm³
- Colors
- MediumDark green
- Streak
- Light green
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Trigonal
- Crystal habit
- Rhombohedral crystals, crusts, massive
- Cleavage
- Perfect on {201}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- A secondary mineral in near-surface, low-temperature, oxidation zones under increasingly arid conditions
Where rockhounds find paratacamite-(mg)
Classic worldwide localities
- Chile
- Mexico
- Italy
Field-hunting tip
Where it forms: A secondary mineral in near-surface, low-temperature, oxidation zones under increasingly arid conditions. If you start seeing anhydrite, atacamite, chalcopyrite in float, you are in the right ground. Typical habit: rhombohedral crystals, crusts, massive. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify paratacamite-(mg)?+
Where is paratacamite-(mg) found?+
Is paratacamite-(mg) safe to handle?+
What rocks look like paratacamite-(mg)?+
What minerals are found with paratacamite-(mg)?+
What kind of rock does paratacamite-(mg) form in?+
What is paratacamite-(mg) used for?+
Find paratacamite-(mg) on the map
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