Althupite is a complex secondary uranium mineral that forms thin, platy yellow to yellow-green crystals, often found in radiating clusters. It is an extremely rare phosphate species primarily known from the oxidized zones of uranium-bearing pegmatites in the Democratic Republic of the Congo. Due to its radioactive nature and scarcity, it is sought after primarily by advanced radioactive mineral collectors.
Is this althupite?
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 althupite with a known reference. Althupite sits at Mohs 3-4 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Althupite leaves a yellow streak.
- 3Read the lusterHold the specimen under a strong light. Althupite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: yellow, yellow-green.
- 5Look at form & habitCrystal system: triclinic. Typical habit: platy crystals, radial aggregates.
Often confused with
Althupite vs. its common look-alikes — and how to tell them apart in the field.
How to tell apart: Streak differs — Althupite leaves yellow, Autunite leaves pale yellow; luster reads vitreous on Althupite and pearly on Autunite.
How to tell apart: Streak differs — Althupite leaves yellow, Torbernite leaves pale green.
Often found alongside althupite
Minerals reported to co-occur with althupite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- AlTh(UO₂)₂(PO₄)₄(OH)₃·15H₂O
- Mohs hardness
- 3-4
- Density
- 4.43 g/cm³
- Colors
- Streak
- Yellow
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Triclinic
- Crystal habit
- Platy Crystals, Radial Aggregates
- Cleavage
- Perfect in One Direction
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Granite Pegmatites
- Typical price
- $100-500 per specimen
Where rockhounds find althupite
Classic worldwide localities
- Kobokobo pegmatite, Democratic Republic of the Congo
Field-hunting tip
Look in granite pegmatites country — that is the host setting where althupite typically forms. If you start seeing meta-autunite, dumontite, triangulite in float, you are in the right ground. Field specimens usually show a platy crystals, radial aggregates habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify althupite?+
Where is althupite found?+
How much is althupite worth?+
Is althupite safe to handle?+
What rocks look like althupite?+
What minerals are found with althupite?+
What kind of rock does althupite form in?+
What is althupite used for?+
Find althupite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
