Svornostite-(K) is a rare secondary uranium mineral found within the oxidation zones of uranium deposits. It typically forms delicate, yellow acicular to fibrous crystalline sprays often associated with other uranium-bearing sulfates.
Is this svornostite-(k)?
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 svornostite-(k) with a known reference. Svornostite-(K) sits at Mohs 2-3 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Svornostite-(K) leaves a yellow streak.
- 3Read the lusterHold the specimen under a strong light. Svornostite-(K) typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: yellow.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: acicular to fibrous aggregates.
Often confused with
Svornostite-(K) vs. its common look-alikes — and how to tell them apart in the field.
Often found alongside svornostite-(k)
Minerals reported to co-occur with svornostite-(k). Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- K₂Mg(UO₂)₂(SO₄)₄·8H₂O
- Mohs hardness
- 2-3
- Density
- 3.32 g/cm³
- Colors
- Streak
- Yellow
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Monoclinic
- Crystal habit
- Acicular to Fibrous Aggregates
- Cleavage
- None
- Fluorescence
- Bright Yellow-green Under UV
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Hydrothermal Uranium Veins
- Typical price
- $50-300 per specimen
Where rockhounds find svornostite-(k)
Classic worldwide localities
- Svornost Mine, Jáchymov, Czech Republic
Field-hunting tip
Look in hydrothermal uranium veins country — that is the host setting where svornostite-(k) typically forms. If you start seeing johannite, uranyl sulfates, gypsum in float, you are in the right ground. Field specimens usually show a acicular to fibrous aggregates habit, so train your eye for that shape before scanning the outcrop.



