Brochantite is a vibrant, deep-green copper sulfate mineral that typically forms as acicular or prismatic crystal clusters in the oxidized zones of copper deposits. It is often found as a secondary mineral coating other copper minerals, and collectors value it for its intense, vitreous green color.
Is this brochantite?
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 brochantite with a known reference. Brochantite sits at Mohs 3.5-4, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Brochantite leaves a pale-green streak.
- 3Read the lusterHold the specimen under a strong light. Brochantite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: emerald-green, dark-green, bright-green.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: acicular crystals, prismatic, drusy crusts, botryoidal.
Often confused with
Brochantite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Brochantite leaves pale-green, Malachite leaves light green.
How to tell apart: Streak differs, so Brochantite leaves pale-green, Antlerite leaves light green.
How to tell apart: Streak differs, so Brochantite leaves pale-green, Atacamite leaves apple green; luster reads vitreous on Brochantite and adamantine to vitreous on Atacamite.
Often found alongside brochantite
Minerals reported to co-occur with brochantite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Cu₄(SO₄)(OH)₆
- Mohs hardness
- 3.5-4
- Density
- 3.9-4.0 g/cm³
- Streak
- Pale-green
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Monoclinic
- Crystal habit
- Acicular Crystals, Prismatic, Drusy Crusts, Botryoidal
- Cleavage
- Perfect in One Direction
- Rarity
- Common
- Uses
- Collector, Specimen
- Host rock
- Oxidized Copper Ore Deposits
- Typical price
- $10-150 depending on specimen size and crystal quality
Where rockhounds find brochantite
2 mapped spotsClassic worldwide localities
- Bisbee, Arizona (USA)
- Chuquicamata, Chile
- Tsumeb, Namibia
- Lavrion, Greece
- Burra, Australia
Field-hunting tip
Look in oxidized copper ore deposits country, the host setting where brochantite typically forms. If you start seeing malachite, chrysocolla, cuprite in float, you are in the right ground. Field specimens usually show a acicular crystals, prismatic, drusy crusts, botryoidal habit, so train your eye for that shape before scanning the outcrop. In the U.S., the densest reported localities are in New Mexico, Utah. Start trip planning there.
Common questions
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Find brochantite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
