Galloplumbogummite is an exceptionally rare member of the plumbogummite group, forming as a secondary mineral in lead-rich oxidation zones. It is most commonly found as small, dull, yellowish-brown encrustations or botryoidal masses, often misidentified without micro-analysis due to its similarity to other group members.
Is this galloplumbogummite?
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 galloplumbogummite with a known reference. Galloplumbogummite sits at Mohs 4-5 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Galloplumbogummite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Galloplumbogummite typically shows a greasy luster.
- 4Match the color rangeCompare against the expected color range: yellow, brown, white, colorless.
- 5Look at form & habitCrystal system: trigonal. Typical habit: massive, crusts, botryoidal.
Often confused with
Galloplumbogummite vs. its common look-alikes — and how to tell them apart in the field.
Often found alongside galloplumbogummite
Minerals reported to co-occur with galloplumbogummite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- PbGa(PO₄)(OH)₂
- Mohs hardness
- 4-5
- Density
- 4.6-4.8 g/cm³
- Streak
- White
- Luster
- Greasy
- Transparency
- Translucent
- Crystal system
- Trigonal
- Crystal habit
- Massive, Crusts, Botryoidal
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Oxidized Zones of Lead-bearing Hydrothermal Ore Deposits
- Typical price
- $50-300 per specimen
Where rockhounds find galloplumbogummite
Classic worldwide localities
- Tsumeb Mine, Namibia
Field-hunting tip
Look in oxidized zones of lead-bearing hydrothermal ore deposits country — that is the host setting where galloplumbogummite typically forms. If you start seeing galena, cerussite, mimetite in float, you are in the right ground. Field specimens usually show a massive, crusts, botryoidal habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify galloplumbogummite?+
Where is galloplumbogummite found?+
How much is galloplumbogummite worth?+
Is galloplumbogummite safe to handle?+
What rocks look like galloplumbogummite?+
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Find galloplumbogummite on the map
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