Canosioite is an extremely rare arsenate mineral that occurs as small, vibrant yellow to orange-yellow crystals. It is primarily found in hydrothermal veins associated with specific lead and iron-rich deposits in the Italian Alps. Due to its rarity and specific chemical composition, it is highly sought after by advanced systematic mineral collectors.
Is this canosioite?
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 canosioite with a known reference. Canosioite sits at Mohs 6-6.5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: pale yellow.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous.
- 4Match the color rangeCompare against the expected color range: reddish brown.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: tabular crystals, subparallel aggregates.
Often confused with
Canosioite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Canosioite is noticeably harder (Mohs 6-6.5 vs. 3.5); streak differs, so Canosioite leaves pale yellow, Carminite leaves reddish yellow.
How to tell apart: Canosioite is noticeably harder (Mohs 6-6.5 vs. 4.5); luster reads vitreous on Canosioite and dull to vitreous on fractures on Duftite.
Often found alongside canosioite
Minerals reported to co-occur with canosioite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Ba₂Fe(AsO₄)₂(OH)
- Mohs hardness
- 6-6.5
- Density
- 4.943 g/cm³
- Colors
- Streak
- Pale yellow
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Monoclinic
- Crystal habit
- Tabular crystals, subparallel aggregates
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- From the dumps of a vein-controlled, polymetallic hydrothermal deposit
Where rockhounds find canosioite
Classic worldwide localities
- Valletta mine, Vallone della Valletta, Canosio municipality, Maira Valley, Cuneo Province, Piedmont, Italy
Field-hunting tip
Where it forms: From the dumps of a vein-controlled, polymetallic hydrothermal deposit. If you start seeing aegirine, barite, calcite in float, you are in the right ground. Typical habit: tabular crystals, subparallel aggregates. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify canosioite?+
Where is canosioite found?+
Is canosioite safe to handle?+
What rocks look like canosioite?+
What minerals are found with canosioite?+
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Find canosioite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
