Schertelite is a rare phosphate mineral formed through the reaction of bat guano with limestone in cave environments. It typically occurs as small, colorless to white tabular crystals or thin crusts associated with other guano minerals like struvite.
Is this schertelite?
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 schertelite with a known reference. Schertelite sits at Mohs 2 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Schertelite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Schertelite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: white, colorless.
- 5Look at form & habitCrystal system: triclinic. Typical habit: tabular crystals, crusts.
Often confused with
Schertelite vs. its common look-alikes — and how to tell them apart in the field.
Often found alongside schertelite
Minerals reported to co-occur with schertelite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- (NH₄)₂(Mg)(HPO₄)₂·4H₂O
- Mohs hardness
- 2
- Density
- 1.89 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Triclinic
- Crystal habit
- Tabular Crystals, Crusts
- Cleavage
- Distinct
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Guano-derived Deposits in Limestone Caves
- Typical price
- $50-300 per specimen
Where rockhounds find schertelite
Classic worldwide localities
- Skipton Caves, Victoria, Australia
Field-hunting tip
Look in guano-derived deposits in limestone caves country — that is the host setting where schertelite typically forms. If you start seeing struvite, newberyite, hannayite in float, you are in the right ground. Field specimens usually show a tabular crystals, crusts habit, so train your eye for that shape before scanning the outcrop.



