Waterhouseite is a very rare manganese phosphate mineral occurring as dark, tabular crystals in manganese-rich metamorphic environments. It is primarily sought by advanced mineral collectors specializing in phosphate species or manganese minerals, as it is found in very few locations worldwide.
Is this waterhouseite?
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 waterhouseite with a known reference. Waterhouseite 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. Waterhouseite leaves a brown streak.
- 3Read the lusterHold the specimen under a strong light. Waterhouseite typically shows a vitreous to pearly luster.
- 4Match the color rangeCompare against the expected color range: black, brown.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: tabular crystals.
Often confused with
Waterhouseite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Waterhouseite leaves brown, Iron Ore leaves reddish-brown to black; luster reads vitreous to pearly on Waterhouseite and metallic to submetallic on Iron Ore.
How to tell apart: Streak differs, so Waterhouseite leaves brown, Manaccanite leaves black; luster reads vitreous to pearly on Waterhouseite and submetallic on Manaccanite.
Often found alongside waterhouseite
Minerals reported to co-occur with waterhouseite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Mn₇(PO₄)₂(OH)₈
- Mohs hardness
- 4-5
- Density
- 3.8 g/cm³
- Streak
- Brown
- Luster
- Vitreous to Pearly
- Transparency
- Transparent
- Crystal system
- Monoclinic
- Crystal habit
- Tabular Crystals
- Cleavage
- Perfect On (100) and Probable On (001)
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Metamorphosed Manganese Ore Deposits
Where rockhounds find waterhouseite
Classic worldwide localities
- Iron Monarch quarry, Iron Knob, South Australia
Field-hunting tip
Look in metamorphosed manganese ore deposits country, the host setting where waterhouseite typically forms. If you start seeing hausmannite, braunite, baryte in float, you are in the right ground. Field specimens usually show a tabular crystals habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify waterhouseite?+
Where is waterhouseite found?+
What rocks look like waterhouseite?+
What minerals are found with waterhouseite?+
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Find waterhouseite on the map
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