Artsmithite is a rare mercury-aluminum arsenate mineral known for its distinctive white to pale yellow platy crystal habit. It is found primarily in mercury-rich hydrothermal deposits and requires professional identification due to its similarity to other rare secondary minerals.
Is this artsmithite?
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 artsmithite with a known reference. Artsmithite sits at Mohs 2-3, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: white to cream.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous.
- 4Match the color rangeCompare against the expected color range: white, colorless.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: acicular, fibrous.
Often confused with
Artsmithite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Artsmithite leaves white to cream, Mixite leaves pale bluish green.
How to tell apart: Streak differs, so Artsmithite leaves white to cream, Pharmacosiderite leaves yellowish green; luster reads vitreous on Artsmithite and adamantine to greasy on Pharmacosiderite.
Often found alongside artsmithite
Minerals reported to co-occur with artsmithite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Hg₄Al(PO₄)₁.₇₄(OH)₁.₇₈
- Mohs hardness
- 2-3
- Density
- 6.40 g/cm³
- Streak
- White to cream
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Monoclinic
- Crystal habit
- Acicular, fibrous
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- A weathering product filling fractures in a cinnabar and fluorapatite-bearing sandstone
Where rockhounds find artsmithite
Classic worldwide localities
- Funderburk Prospect, Pike County, Arkansas, USA (type locality)
Field-hunting tip
Where it forms: A weathering product filling fractures in a cinnabar and fluorapatite-bearing sandstone. If you start seeing quartz, goethite, dickite in float, you are in the right ground. Typical habit: acicular, fibrous. Train your eye for that shape before scanning the outcrop.
Common questions
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Find artsmithite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
