Gartrellite is a rare secondary mineral found in the oxidation zones of arsenic-rich mineral deposits. Collectors typically search for its characteristic bright green, crust-like or micro-crystalline coatings on host rock surfaces.
Is this gartrellite?
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 gartrellite with a known reference. Gartrellite 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. Streak: bright yellow.
- 3Read the lusterHold the specimen under a strong light. Luster: chalky.
- 4Match the color rangeCompare against the expected color range: greenish yellow, yellow.
- 5Look at form & habitCrystal system: triclinic. Typical habit: encrustations.
Often confused with
Gartrellite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Gartrellite leaves bright yellow, Tsumcorite leaves yellow; luster reads chalky on Gartrellite and vitreous on Tsumcorite.
How to tell apart: Streak differs, so Gartrellite leaves bright yellow, Duftite leaves pale green to white; luster reads chalky on Gartrellite and dull to vitreous on fractures on Duftite.
How to tell apart: Streak differs, so Gartrellite leaves bright yellow, Conichalcite leaves green; luster reads chalky on Gartrellite and vitreous to somewhat greasy on Conichalcite.
Often found alongside gartrellite
Minerals reported to co-occur with gartrellite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- PbCuFe³⁺(AsO₄)₂(OH,H₂O)₂
- Mohs hardness
- 4.5
- Density
- 5.38-5.43 g/cm³
- Colors
- Streak
- Bright yellow
- Luster
- Chalky
- Transparency
- Transparent
- Crystal system
- Triclinic
- Crystal habit
- Encrustations
- Cleavage
- Perfect on {111}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- A rare mineral in an oxidized mineralized shear zone cutting graywackes and shales (Anticline prospect, Australia); on fine-grained quartz-spessartine rocks (Broken Hill, Australia)
Where rockhounds find gartrellite
Classic worldwide localities
- Centennial Eureka mine, Tintic district, Juab Co., Utah, USA
- Anticline and Bali Lo copper prospects, 11 km west-southwest of Ashburton Downs homestead, Capricorn Range, Western Australia, and in the Kintore open cut, Broken Hill, New South Wales, Australia
- Reichenbach, near Bensheim, Hesse, and in the Clara Mine, near Oberwolfach, Black Forest, Germany
- Tsumeb, Namibia
Field-hunting tip
Where it forms: A rare mineral in an oxidized mineralized shear zone cutting graywackes and shales (Anticline prospect, Australia); on fine-grained quartz-spessartine rocks (Broken Hill, Australia). If you start seeing secondary copper minerals, quartz, clay minerals in float, you are in the right ground. Typical habit: encrustations. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify gartrellite?+
Where is gartrellite found?+
Is gartrellite safe to handle?+
What rocks look like gartrellite?+
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Find gartrellite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
