Shannonite is a rare lead carbonate mineral found in the oxidized zones of lead-bearing ore deposits. Collectors typically seek it for its distinct bright yellow to greenish-white tabular crystals found in classic localities like the Mammoth-St. Anthony Mine.
Is this shannonite?
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 shannonite with a known reference. Shannonite sits at Mohs 3-3.5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: white.
- 3Read the lusterHold the specimen under a strong light. Luster: waxy.
- 4Match the color rangeCompare against the expected color range: white.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: encrustations, platy, porcelainous.
Often confused with
Shannonite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside shannonite
Minerals reported to co-occur with shannonite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Pb₂CO₃O
- Mohs hardness
- 3-3.5
- Density
- 9.31 g/cm³
- Colors
- Streak
- White
- Luster
- Waxy
- Transparency
- Opaque
- Crystal system
- Orthorhombic
- Crystal habit
- Encrustations, platy, porcelainous
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- A rare secondary mineral formed in the oxidation zone, probably by acidic groundwater reacting with cerussite, in a lead ore deposit (Grand Reef mine, Arizona, USA)
Where rockhounds find shannonite
Classic worldwide localities
- Grand Reef mine, about six km northeast of Klondyke, Aravaipa district, Graham Co., Arizona, USA
Field-hunting tip
Where it forms: A rare secondary mineral formed in the oxidation zone, probably by acidic groundwater reacting with cerussite, in a lead ore deposit (Grand Reef mine, Arizona, USA). If you start seeing cerussite, litharge, massicot in float, you are in the right ground. Typical habit: encrustations, platy, porcelainous. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify shannonite?+
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Find shannonite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
