Ardaite is an extremely rare lead antimony sulfosalt found in specific hydrothermal deposits. It is most commonly identified by its distinct acicular, needle-like crystal habit and typically grayish green to bluish green color.
Is this ardaite?
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 ardaite with a known reference. Ardaite sits at Mohs 2.5-3, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: gray.
- 3Read the lusterHold the specimen under a strong light. Luster: metallic.
- 4Match the color rangeCompare against the expected color range: green gray.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: acicular, aggregates, microscopic crystals.
Often confused with
Ardaite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Ardaite leaves gray, Jamesonite leaves black. grayish.
How to tell apart: Streak differs, so Ardaite leaves gray, Boulangerite leaves brownish.
How to tell apart: Streak differs, so Ardaite leaves gray, Plagionite leaves blackish lead-gray, deep red-brown.
Often found alongside ardaite
Minerals reported to co-occur with ardaite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Pb₁₇Sb₁₅S₃₅Cl₉
- Mohs hardness
- 2.5-3
- Density
- 6.44 g/cm³
- Colors
- Green gray
- Streak
- Gray
- Luster
- Metallic
- Transparency
- Opaque
- Crystal system
- Monoclinic
- Crystal habit
- Acicular, aggregates, microscopic crystals
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector, Scientific research
- Host rock
- Very rare in polymetallic ore deposits
Where rockhounds find ardaite
Classic worldwide localities
- Madjarovo, eastern Rhodope Mountains, Bulgaria (type locality)
- Dressfall mine, Gruvåsen, Bergslagen metallic province, Sweden
Field-hunting tip
Where it forms: Very rare in polymetallic ore deposits. If you start seeing galena, nadorite, chlorian robinsonite in float, you are in the right ground. Typical habit: acicular, aggregates, microscopic crystals. Train your eye for that shape before scanning the outcrop.
Common questions
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Find ardaite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
