Jörgkellerite is a rare sodium manganese phosphate, typically brown. It is a product of low-temperature, oxidative alteration of gregoryite-nyerereite carbonatitic lavas. Associated minerals include fluorite, khanneshite and barite. It was first described from Oldoinyo Lengai volcano, Gregory Rift, northern Tanzania.
Is this jörgkellerite?
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 jörgkellerite with a known reference. Jörgkellerite sits at Mohs 3, 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.
- 4Match the color rangeCompare against the expected color range: brown.
- 5Look at form & habitCrystal system: trigonal. Typical habit: tabular crystals, clusters.
Often confused with
Jörgkellerite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside jörgkellerite
Minerals reported to co-occur with jörgkellerite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Na₃Mn³⁺₃(PO₄)₂(CO₃)O₂·5H₂O
- Mohs hardness
- 3
- Density
- 2.56 g/cm³
- Colors
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Trigonal
- Crystal habit
- Tabular crystals, clusters
- Cleavage
- Perfect on {001}, micaceous
- Rarity
- Rare
- Uses
- Collector
- Host rock
- A product of low-temperature, oxidative alteration of gregoryite-nyerereite carbonatitic lavas
Where rockhounds find jörgkellerite
Classic worldwide localities
- Oldoinyo Lengai volcano, Gregory Rift, northern Tanzania
Field-hunting tip
Where it forms: A product of low-temperature, oxidative alteration of gregoryite-nyerereite carbonatitic lavas. If you start seeing fluorite, khanneshite, barite in float, you are in the right ground. Typical habit: tabular crystals, clusters. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify jörgkellerite?+
Where is jörgkellerite found?+
What rocks look like jörgkellerite?+
What minerals are found with jörgkellerite?+
What kind of rock does jörgkellerite form in?+
What is jörgkellerite used for?+
Find jörgkellerite on the map
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