Perroudite is a rare mercury silver halide mineral typically found as tiny, vibrant red, acicular needles in oxidized ore deposits. It is highly prized by collectors for its brilliant color and crystal habit, though it is almost exclusively found as microscopic specimens.
Is this perroudite?
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 perroudite with a known reference. Perroudite 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. Perroudite leaves a orange-red streak.
- 3Read the lusterHold the specimen under a strong light. Perroudite typically shows a adamantine luster.
- 4Match the color rangeCompare against the expected color range: scarlet red, bright red, dark red.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: acicular crystals, fibrous radiating sprays.
Often confused with
Perroudite vs. its common look-alikes — and how to tell them apart in the field.
How to tell apart: Streak differs — Perroudite leaves orange-red, Cinnabar leaves scarlet.
How to tell apart: Streak differs — Perroudite leaves orange-red, Iodargyrite leaves yellow; luster reads adamantine on Perroudite and resinous on Iodargyrite.
Often found alongside perroudite
Minerals reported to co-occur with perroudite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Hg₅Ag₄S₅(I,Br,Cl)₂
- Mohs hardness
- 2
- Density
- 6.6 g/cm³
- Streak
- Orange-red
- Luster
- Adamantine
- Transparency
- Translucent
- Crystal system
- Orthorhombic
- Crystal habit
- Acicular Crystals, Fibrous Radiating Sprays
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Oxidized Hydrothermal Zones
- Typical price
- $100-500+ for micro-specimens
Where rockhounds find perroudite
Classic worldwide localities
- Cap Garonne mine, France
- Torrecillas mine, Chile
- Gold Hill, Utah, USA
Field-hunting tip
Look in oxidized hydrothermal zones country — that is the host setting where perroudite typically forms. If you start seeing cinnabar, metacinnabar, boleite in float, you are in the right ground. Field specimens usually show a acicular crystals, fibrous radiating sprays habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify perroudite?+
Where is perroudite found?+
How much is perroudite worth?+
Is perroudite safe to handle?+
What rocks look like perroudite?+
What minerals are found with perroudite?+
What kind of rock does perroudite form in?+
What is perroudite used for?+
Find perroudite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
