Thalliumpharmacosiderite is a rare member of the pharmacosiderite group characterized by the inclusion of thallium in its chemical structure. It typically presents as small, yellow to yellowish-green cubic or pseudocubic crystals found in the oxidized zones of arsenic-rich mineral deposits. Due to its toxicity and rarity, it is sought primarily by advanced mineral collectors specializing in rare species or rare-element minerals.
Is this thalliumpharmacosiderite?
4-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 thalliumpharmacosiderite with a known reference. Thalliumpharmacosiderite sits at Mohs 2.5, softer than the next harder reference, harder than the previous one.
- 2Read the lusterHold the specimen under a strong light. Luster: vitreous.
- 3Match the color rangeCompare against the expected color range: yellow, yellowish-green, brown.
- 4Look at form & habitCrystal system: cubic. Typical habit: pseudocubic crystals, massive.
Often confused with
Thalliumpharmacosiderite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside thalliumpharmacosiderite
Minerals reported to co-occur with thalliumpharmacosiderite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- TlFe₄(AsO₄)₃(OH)₄·4H₂O
- Mohs hardness
- 2.5
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Cubic
- Crystal habit
- Pseudocubic crystals, massive
- Rarity
- Rare
- Uses
- Collector
- Host rock
- oxidized arsenic-rich hydrothermal deposits
Where rockhounds find thalliumpharmacosiderite
Classic worldwide localities
- Crven Dol Canyon, Rozsdan region, Macedonia (type locality)
Field-hunting tip
Where it forms: oxidized arsenic-rich hydrothermal deposits. If you start seeing pharmacosiderite, arsenopyrite, goethite in float, you are in the right ground. Typical habit: pseudocubic crystals, massive. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify thalliumpharmacosiderite?+
Where is thalliumpharmacosiderite found?+
Is thalliumpharmacosiderite safe to handle?+
What rocks look like thalliumpharmacosiderite?+
What minerals are found with thalliumpharmacosiderite?+
What kind of rock does thalliumpharmacosiderite form in?+
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Find thalliumpharmacosiderite on the map
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