Dessauite-(Y) is an extremely rare mineral belonging to the crichtonite group, typically occurring as small black rhombohedral crystals in alpine clefts. Collectors prioritize these specimens due to their complex chemical composition and limited localities in the Swiss Alps. Always handle with care due to its uranium content.
Is this dessauite-(y)?
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 dessauite-(y) with a known reference. Dessauite-(Y) sits at Mohs 6-7 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Dessauite-(Y) leaves a brownish-black streak.
- 3Read the lusterHold the specimen under a strong light. Dessauite-(Y) typically shows a submetallic luster.
- 4Match the color rangeCompare against the expected color range: black, brownish-black.
- 5Look at form & habitCrystal system: trigonal. Typical habit: rhombohedral crystals.
Often confused with
Dessauite-(Y) vs. its common look-alikes — and how to tell them apart in the field.
How to tell apart: Streak differs — Dessauite-(Y) leaves brownish-black, Crichtonite leaves black.
How to tell apart: Streak differs — Dessauite-(Y) leaves brownish-black, Lindsleyite leaves black.
How to tell apart: Streak differs — Dessauite-(Y) leaves brownish-black, Mathiasite leaves brownish black.
Often found alongside dessauite-(y)
Minerals reported to co-occur with dessauite-(y). Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- SrPb(Mn,Y,U)Fe₂(Ti,Fe,Cr,Mg)₁₈O₃₈
- Mohs hardness
- 6-7
- Density
- 4.55 g/cm³
- Colors
- Streak
- Brownish-black
- Luster
- Submetallic
- Transparency
- Opaque
- Crystal system
- Trigonal
- Crystal habit
- Rhombohedral Crystals
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Alpine-type Hydrothermal Veins
- Typical price
- $50-300 per thumbnail specimen
Where rockhounds find dessauite-(y)
Classic worldwide localities
- Binn Valley, Switzerland
- Piz Casatscha, Switzerland
Field-hunting tip
Look in alpine-type hydrothermal veins country — that is the host setting where dessauite-(y) typically forms. If you start seeing anatase, brookite, hematite in float, you are in the right ground. Field specimens usually show a rhombohedral crystals habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify dessauite-(y)?+
Where is dessauite-(y) found?+
How much is dessauite-(y) worth?+
Is dessauite-(y) safe to handle?+
What rocks look like dessauite-(y)?+
What minerals are found with dessauite-(y)?+
What kind of rock does dessauite-(y) form in?+
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Find dessauite-(y) on the map
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