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.

Hardness
2-3
Mohs
Luster
Vitreous
Streak
Yellow
Transparency
Translucent

Is this svornostite-(k)?

5-step field check

Run through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.

  • 1
    Test the hardness
    Try 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.
  • 2
    Check the streak
    Drag the specimen across an unglazed porcelain plate. Svornostite-(K) leaves a yellow streak.
  • 3
    Read the luster
    Hold the specimen under a strong light. Svornostite-(K) typically shows a vitreous luster.
  • 4
    Match the color range
    Compare against the expected color range: yellow.
  • 5
    Look at form & habit
    Crystal 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.

Common questions

How do you identify svornostite-(k)?+
Mohs hardness is 2-3. It typically shows a vitreous luster. The streak is yellow. Common colors include yellow.
Where is svornostite-(k) found?+
Notable localities include Svornost Mine, Jáchymov, Czech Republic.
How much is svornostite-(k) worth?+
Typical asking prices fall in the range of $50-300 per specimen. Quality, size, and provenance can move individual specimens well outside that range.
Is svornostite-(k) safe to handle?+
This mineral is radioactive. It contains toxic constituents. This mineral contains uranium and is radioactive. Handle with gloves, store in a sealed container, and wash hands thoroughly after handling. Do not inhale dust or ingest particles. Handle with care, avoid grinding or breathing dust, and store separately.
What rocks look like svornostite-(k)?+
Svornostite-(K) is most often confused with Johannite, Zippeite. A quick hardness test and a streak check separate the look-alikes faster than color alone.
What minerals are found with svornostite-(k)?+
Svornostite-(K) commonly co-occurs with Johannite, Uranyl sulfates, Gypsum. Spotting any of these in float or country rock is a useful trip signal.
What kind of rock does svornostite-(k) form in?+
Svornostite-(K) typically forms in hydrothermal uranium veins. Working float back to the host body is the standard way to chase a fresh occurrence.
What is svornostite-(k) used for?+
Svornostite-(K) is used in collector.

Find svornostite-(k) on the map

RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.

Download on the App StoreGet it on Google Play