Gladite is a rare lead copper bismuth sulfide mineral that typically forms as acicular or bladed crystals within hydrothermal veins. It is most easily identified by its metallic, lead-gray appearance and its distinct occurrence alongside other bismuth-bearing sulfosalts.
Is this gladite?
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 gladite with a known reference. Gladite sits at Mohs 2-3, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: black.
- 3Read the lusterHold the specimen under a strong light. Luster: metallic.
- 4Match the color rangeCompare against the expected color range: lead gray, gray, tin white.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: prismatic.
Often confused with
Gladite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside gladite
Minerals reported to co-occur with gladite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- PbCuBi₅S₉
- Mohs hardness
- 2-3
- Density
- 6.96 g/cm³
- Streak
- Black
- Luster
- Metallic
- Transparency
- Opaque
- Crystal system
- Orthorhombic
- Crystal habit
- Prismatic
- Cleavage
- Good on {010}, fair on {100}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Of hydrothermal origin
Where rockhounds find gladite
Classic worldwide localities
- Comstock mine, Dos Cabezas, Cochise Co., Arizona, USA
- Gladhammar, Kalmar, Sweden (type locality)
- Bleka, Telemark, Norway
- Kochbulak gold deposit, Chatkal-Kuramin Mountains, eastern Uzbekistan
- Krupka, Czech Republic
- Baia Borşa, Baia Mare (Nagybánya), Romania
Field-hunting tip
Where it forms: Of hydrothermal origin. If you start seeing bismuthinite-aikinite, galenobismutite, makovickyite in float, you are in the right ground. Typical habit: prismatic. Train your eye for that shape before scanning the outcrop.
Common questions
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Find gladite on the map
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