Antlerite is a secondary copper sulfate mineral often found as emerald-green acicular crystals or massive crusts in the oxidized zones of copper deposits. It is frequently confused with the closely related mineral brochantite, though it is usually distinguished by its specific crystal habit and chemical testing.
Is this antlerite?
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 antlerite with a known reference. Antlerite sits at Mohs 3.5 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Antlerite leaves a light green streak.
- 3Read the lusterHold the specimen under a strong light. Antlerite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: emerald green, dark green, blackish green.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: acicular or prismatic crystals, commonly in crusts or radiating aggregates.
Often confused with
Antlerite vs. its common look-alikes — and how to tell them apart in the field.
How to tell apart: Streak differs — Antlerite leaves light green, Brochantite leaves pale-green.
How to tell apart: Streak differs — Antlerite leaves light green, Atacamite leaves apple green; luster reads vitreous on Antlerite and adamantine to vitreous on Atacamite.
Often found alongside antlerite
Minerals reported to co-occur with antlerite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Cu₃SO₄(OH)₄
- Mohs hardness
- 3.5
- Density
- 3.9 g/cm³
- Streak
- Light Green
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Orthorhombic
- Crystal habit
- Acicular or Prismatic Crystals, Commonly in Crusts or Radiating Aggregates
- Cleavage
- Perfect in One Direction
- Rarity
- Uncommon
- Uses
- Collector, Specimen
- Host rock
- Oxidized Zones of Copper Ore Deposits
- Typical price
- $10-100 for small to cabinet sized specimens
Where rockhounds find antlerite
1 mapped spotsClassic worldwide localities
- Chuquicamata, Chile
- Bisbee, Arizona, USA
- Potrerillos, Chile
- Tsumeb, Namibia
Field-hunting tip
Look in oxidized zones of copper ore deposits country — that is the host setting where antlerite typically forms. If you start seeing brochantite, chalcanthite, gypsum in float, you are in the right ground. Field specimens usually show a acicular or prismatic crystals, commonly in crusts or radiating aggregates habit, so train your eye for that shape before scanning the outcrop. In the U.S., the densest reported localities are in Utah — start trip planning there.
Common questions
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Find antlerite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
