Phosphorrösslerite is a rare hydrous magnesium phosphate mineral typically occurring as fragile, colorless to white blades or radial sprays. It is an secondary mineral found in oxidized zones of ore deposits, often associated with guano-rich environments or phosphate-bearing hydrothermal veins.
Is this phosphorrösslerite?
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 phosphorrösslerite with a known reference. Phosphorrösslerite sits at Mohs 2.5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: white.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous, changing to dull on exposure.
- 4Match the color rangeCompare against the expected color range: colorless, yellowish.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: bladed crystals, radial aggregates, crusts.
Often confused with
Phosphorrösslerite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside phosphorrösslerite
Minerals reported to co-occur with phosphorrösslerite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- MgHPO₄·7H₂O
- Mohs hardness
- 2.5
- Density
- 1.725 g/cm³
- Streak
- White
- Luster
- Vitreous, changing to dull on exposure
- Transparency
- Semitransparent, opaque on exposure
- Crystal system
- Monoclinic
- Crystal habit
- Bladed crystals, radial aggregates, crusts
- Cleavage
- Perfect on {010}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In cold (10°C) wet muck in an abandoned mine
Where rockhounds find phosphorrösslerite
Classic worldwide localities
- Stüblbau works, Schellgaden, Austria
Field-hunting tip
Where it forms: In cold (10°C) wet muck in an abandoned mine. If you start seeing newberyite, vivianite, guanine in float, you are in the right ground. Typical habit: bladed crystals, radial aggregates, crusts. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify phosphorrösslerite?+
Where is phosphorrösslerite found?+
What rocks look like phosphorrösslerite?+
What minerals are found with phosphorrösslerite?+
What kind of rock does phosphorrösslerite form in?+
What is phosphorrösslerite used for?+
Find phosphorrösslerite on the map
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