Arsenoflorencite-(La) is a rare arsenic-bearing member of the alunite supergroup typically found as small rhombohedral crystals. It is a secondary mineral that occurs in weathered hydrothermal deposits and is highly sought after by systematic mineral collectors.
Is this arsenoflorencite-(la)?
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 arsenoflorencite-(la) with a known reference. Arsenoflorencite-(La) sits at Mohs 3.5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Arsenoflorencite-(La) leaves a very pale pink streak.
- 3Read the lusterHold the specimen under a strong light. Arsenoflorencite-(La) typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: orange-red, pink.
- 5Look at form & habitCrystal system: trigonal. Typical habit: rhombohedral crystals.
Often confused with
Arsenoflorencite-(La) vs. its common look-alikes, and how to tell them apart in the field.

How to tell apart: Florencite-(Ce) is the harder of the two (Mohs 5-6 vs. 3.5); streak differs, so Arsenoflorencite-(La) leaves very pale pink, Florencite-(Ce) leaves white; luster reads vitreous on Arsenoflorencite-(La) and greasy to resinous on Florencite-(Ce).

How to tell apart: Streak differs, so Arsenoflorencite-(La) leaves very pale pink, Arsenogoyazite leaves white.
Often found alongside arsenoflorencite-(la)
Minerals reported to co-occur with arsenoflorencite-(la). Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- LaAsO₄(OH)₆
- Mohs hardness
- 3.5
- Density
- 4.15 g/cm³
- Colors
- Streak
- Very Pale Pink
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Trigonal
- Crystal habit
- Rhombohedral Crystals
- Cleavage
- Distinct On {0001}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Hydrothermal Veins and Secondary Weathering Zones
Where rockhounds find arsenoflorencite-(la)
Classic worldwide localities
- Brazil
- Australia
- China
Field-hunting tip
Look in hydrothermal veins and secondary weathering zones country, the host setting where arsenoflorencite-(la) typically forms. If you start seeing kaolinite, quartz, turquoise 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.



