Sabieite is an extremely rare ammonium iron sulfate mineral that typically forms as a white to yellowish efflorescence on coal seams undergoing combustion. Because it is highly soluble and unstable in humid conditions, it is rarely found in outdoor environments and must be stored in airtight, dry containers to prevent degradation.
Is this sabieite?
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 sabieite with a known reference. Sabieite sits at Mohs 1-2 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Sabieite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Sabieite typically shows a dull luster.
- 4Match the color rangeCompare against the expected color range: yellowish-white, white.
- 5Look at form & habitCrystal system: trigonal. Typical habit: massive, encrustations, efflorescences.
Often confused with
Sabieite vs. its common look-alikes — and how to tell them apart in the field.
How to tell apart: Alunite is the harder of the two (Mohs 3.5-4 vs. 1-2); luster reads dull on Sabieite and vitreous on Alunite.
How to tell apart: Streak differs — Sabieite leaves white, Jarosite leaves yellow; luster reads dull on Sabieite and vitreous on Jarosite.
Often found alongside sabieite
Minerals reported to co-occur with sabieite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- (NH₄)Fe(SO₄)₂
- Mohs hardness
- 1-2
- Density
- 1.79 g/cm³
- Colors
- Streak
- White
- Luster
- Dull
- Transparency
- Opaque
- Crystal system
- Trigonal
- Crystal habit
- Massive, Encrustations, Efflorescences
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector, Scientific Research
- Host rock
- Burned Coal Seams and Pyritic Shale
- Typical price
- $50-300 per specimen
Where rockhounds find sabieite
Classic worldwide localities
- Sabie, Mpumalanga, South Africa
- Burning Mountain, New South Wales, Australia
Field-hunting tip
Look in burned coal seams and pyritic shale country — that is the host setting where sabieite typically forms. If you start seeing jarosite, sulfur, tschermigite in float, you are in the right ground. Field specimens usually show a massive, encrustations, efflorescences habit, so train your eye for that shape before scanning the outcrop.
Common questions
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Find sabieite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
