Arsenogoyazite is a rare member of the alunite supergroup typically found as small, rhombohedral crystals in the oxidation zones of arsenic-rich ore deposits. Collectors primarily seek this mineral from world-class localities like the Tsumeb Mine, where it forms in association with other rare arsenate minerals.
Is this arsenogoyazite?
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 arsenogoyazite with a known reference. Arsenogoyazite 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. Arsenogoyazite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Arsenogoyazite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: white, colorless, pale yellow.
- 5Look at form & habitCrystal system: trigonal. Typical habit: rhombohedral crystals.
Often confused with
Arsenogoyazite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside arsenogoyazite
Minerals reported to co-occur with arsenogoyazite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- SrAl₃(AsO₄)(OH)₆
- Mohs hardness
- 4-5
- Density
- 3.5-3.6 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Trigonal
- Crystal habit
- Rhombohedral Crystals
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Oxidized Hydrothermal Polymetallic Ore Deposits
- Typical price
- $50-300 per specimen
Where rockhounds find arsenogoyazite
Classic worldwide localities
- Tsumeb Mine, Namibia
- Schwarzwald, Germany
Field-hunting tip
Look in oxidized hydrothermal polymetallic ore deposits country, the host setting where arsenogoyazite typically forms. If you start seeing arseniosiderite, scorodite, tsumcorite in float, you are in the right ground. Field specimens usually show a rhombohedral crystals habit, so train your eye for that shape before scanning the outcrop.





