Hotsonite is a rare phosphate mineral typically occurring as massive, white, earthy to fine-grained aggregates. It is primarily found in its type locality in South Africa, often associated with weathered sedimentary phosphate deposits. Due to its limited distribution and nondescript appearance, it is primarily sought after by advanced systematic mineral collectors.
Is this hotsonite?
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 hotsonite with a known reference. Hotsonite sits at Mohs 4 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Hotsonite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Hotsonite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: white, colorless.
- 5Look at form & habitCrystal system: trigonal. Typical habit: fine-grained massive aggregates, microcrystalline.
Often confused with
Hotsonite vs. its common look-alikes — and how to tell them apart in the field.
Often found alongside hotsonite
Minerals reported to co-occur with hotsonite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- NaAl₃(PO₄)₂(OH)₄·H₂O
- Mohs hardness
- 4
- Density
- 2.85 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Trigonal
- Crystal habit
- Fine-grained Massive Aggregates, Microcrystalline
- Cleavage
- None Observed
- Rarity
- Rare
- Uses
- Collector, Scientific Research
- Host rock
- Weathered Phosphate-rich Deposits
- Typical price
- $50-300 per specimen
Where rockhounds find hotsonite
Classic worldwide localities
- Hotson, South Africa
- near Springbok, Northern Cape, South Africa
Field-hunting tip
Look in weathered phosphate-rich deposits country — that is the host setting where hotsonite typically forms. If you start seeing quartz, kaolinite, hematite in float, you are in the right ground. Field specimens usually show a fine-grained massive aggregates, microcrystalline habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify hotsonite?+
Where is hotsonite found?+
How much is hotsonite worth?+
What rocks look like hotsonite?+
What minerals are found with hotsonite?+
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Find hotsonite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
