Coralloite is a rare manganese arsenate mineral that forms distinctive, coral-like botryoidal aggregates. It is primarily found in specialized hydrothermal environments rich in manganese and arsenic, often associated with secondary manganese minerals.
Is this coralloite?
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 coralloite with a known reference. Coralloite sits at Mohs 3-4, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Coralloite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Coralloite typically shows a pearly luster.
- 4Match the color rangeCompare against the expected color range: white, pale pink.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: botryoidal, crusts, radial aggregates.
Often confused with
Coralloite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Coralloite leaves white, Arthurite leaves pale green; luster reads pearly on Coralloite and vitreous on Arthurite.
How to tell apart: Luster reads pearly on Coralloite and adamantine on Pharmacosiderite.
Often found alongside coralloite
Minerals reported to co-occur with coralloite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Mn²⁺Mg₂(AsO₄)₂·8H₂O
- Mohs hardness
- 3-4
- Density
- 2.5 g/cm³
- Streak
- White
- Luster
- Pearly
- Transparency
- Translucent
- Crystal system
- Monoclinic
- Crystal habit
- Botryoidal, Crusts, Radial Aggregates
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Hydrothermal Veins
- Typical price
- $50-300 per specimen
Where rockhounds find coralloite
Classic worldwide localities
- Jianshan mine, Mangshi, China
Field-hunting tip
Look in hydrothermal veins country, the host setting where coralloite typically forms. If you start seeing manganoan calcite, rhodochrosite, arsenopyrite in float, you are in the right ground. Field specimens usually show a botryoidal, crusts, radial aggregates habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify coralloite?+
Where is coralloite found?+
How much is coralloite worth?+
Is coralloite safe to handle?+
What rocks look like coralloite?+
What minerals are found with coralloite?+
What kind of rock does coralloite form in?+
What is coralloite used for?+
Find coralloite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
