Natronambulite is a rare phosphate mineral found primarily in complex granite pegmatites. It is typically identified by its distinct reddish-brown color and its association with other phosphate minerals in hydrothermal replacement zones.
Is this natronambulite?
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 natronambulite with a known reference. Natronambulite sits at Mohs 5.5-6 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Natronambulite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Natronambulite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: red, brownish-red, orange-red.
- 5Look at form & habitCrystal system: triclinic. Typical habit: anhedral to subhedral grains, massive.
Often confused with
Natronambulite vs. its common look-alikes — and how to tell them apart in the field.
Often found alongside natronambulite
Minerals reported to co-occur with natronambulite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- (Na,Li)Mn²⁺₄(PO₄)₃(OH,F)
- Mohs hardness
- 5.5-6
- Density
- 3.55 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Triclinic
- Crystal habit
- Anhedral to Subhedral Grains, Massive
- Cleavage
- Good On {010}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Granite Pegmatites
- Typical price
- $50-300 per specimen
Where rockhounds find natronambulite
Classic worldwide localities
- Hagendorf-Pleystein pegmatite district (Germany)
- Linopolis (Brazil)
- Mangualde (Portugal)
Field-hunting tip
Look in granite pegmatites country — that is the host setting where natronambulite typically forms. If you start seeing triploidite, lithiophilite, quartz in float, you are in the right ground. Field specimens usually show a anhedral to subhedral grains, massive habit, so train your eye for that shape before scanning the outcrop.






