Geocronite is a rare lead-arsenic sulfosalt often found in hydrothermal lead-zinc deposits. It typically presents as metallic lead-gray massive or granular masses, making it visually similar to galena but distinguishable by its specific chemical associations and rarity.
Is this geocronite?
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 geocronite with a known reference. Geocronite sits at Mohs 2.5 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Geocronite leaves a lead-gray streak.
- 3Read the lusterHold the specimen under a strong light. Geocronite typically shows a metallic luster.
- 4Match the color rangeCompare against the expected color range: lead-gray, grayish-blue.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: granular, massive, occasionally tabular crystals.
Often confused with
Geocronite vs. its common look-alikes — and how to tell them apart in the field.
Often found alongside geocronite
Minerals reported to co-occur with geocronite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Pb₁₄As₆S₂₃
- Mohs hardness
- 2.5
- Density
- 6.4-6.5 g/cm³
- Colors
- Streak
- Lead-gray
- Luster
- Metallic
- Transparency
- Opaque
- Crystal system
- Monoclinic
- Crystal habit
- Granular, Massive, Occasionally Tabular Crystals
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Hydrothermal Sulfide Veins
- Typical price
- $20-150 thumbnail, $200+ cabinet specimen
Where rockhounds find geocronite
Classic worldwide localities
- Sala, Sweden
- Miny, Spain
- Pribram, Czech Republic
- Eureka, Nevada, USA
Field-hunting tip
Look in hydrothermal sulfide veins country — that is the host setting where geocronite typically forms. If you start seeing galena, sphalerite, pyrite in float, you are in the right ground. Field specimens usually show a granular, massive, occasionally tabular crystals habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify geocronite?+
Where is geocronite found?+
How much is geocronite worth?+
Is geocronite safe to handle?+
What rocks look like geocronite?+
What minerals are found with geocronite?+
What kind of rock does geocronite form in?+
What is geocronite used for?+
Find geocronite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
