Joséite-B is a rare bismuth telluride sulfide that typically appears as metallic, silver-gray foliated masses or thin plates. It is most often found in hydrothermal quartz veins associated with other bismuth minerals and native gold. Due to its softness and perfect cleavage, specimens should be handled with care to avoid damage to crystal structure.
Is this joséite-b?
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 joséite-b with a known reference. Joséite-B sits at Mohs 1.5-2 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Joséite-B leaves a gray streak.
- 3Read the lusterHold the specimen under a strong light. Joséite-B typically shows a metallic luster.
- 4Match the color rangeCompare against the expected color range: steel-gray, silver-white.
- 5Look at form & habitCrystal system: trigonal. Typical habit: tabular crystals, foliated masses, or lamellar.
Often confused with
Joséite-B vs. its common look-alikes — and how to tell them apart in the field.
How to tell apart: Streak differs — Joséite-B leaves gray, Tetradymite leaves lead-gray.
How to tell apart: Streak differs — Joséite-B leaves gray, Bismuthinite leaves lead-gray.
How to tell apart: Streak differs — Joséite-B leaves gray, Tellurobismuthite leaves lead-gray.
Often found alongside joséite-b
Minerals reported to co-occur with joséite-b. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Bi₄Te₂S
- Mohs hardness
- 1.5-2
- Density
- 8.3-8.6 g/cm³
- Colors
- Streak
- Gray
- Luster
- Metallic
- Transparency
- Opaque
- Crystal system
- Trigonal
- Crystal habit
- Tabular Crystals, Foliated Masses, Or Lamellar
- Cleavage
- Perfect Basal
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Hydrothermal Quartz Veins
- Typical price
- $20-100 thumbnail
Where rockhounds find joséite-b
Classic worldwide localities
- San José, Minas Gerais, Brazil
- Berezovskoe, Urals, Russia
- Dalnegorsk, Russia
- Telemark, Norway
Field-hunting tip
Look in hydrothermal quartz veins country — that is the host setting where joséite-b typically forms. If you start seeing bismuth, gold, pyrite in float, you are in the right ground. Field specimens usually show a tabular crystals, foliated masses, or lamellar habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify joséite-b?+
Where is joséite-b found?+
How much is joséite-b worth?+
Is joséite-b safe to handle?+
What rocks look like joséite-b?+
What minerals are found with joséite-b?+
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Find joséite-b on the map
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