Radtkeite is a rare mercury halide sulfide mineral typically found as small, orange crystals in oxidized mercury deposits. It is specifically known from the McDermitt mine in Nevada, often occurring as encrustations associated with other mercury-bearing minerals. Because it is highly rare and contains mercury, it is sought after primarily by advanced mineral collectors.
Is this radtkeite?
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 radtkeite with a known reference. Radtkeite sits at Mohs 1.5-2 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Radtkeite leaves a yellow-orange streak.
- 3Read the lusterHold the specimen under a strong light. Radtkeite typically shows a adamantine luster.
- 4Match the color rangeCompare against the expected color range: orange, red-orange.
- 5Look at form & habitCrystal system: trigonal. Typical habit: small crystals, coatings.
Often confused with
Radtkeite vs. its common look-alikes — and how to tell them apart in the field.
How to tell apart: Streak differs — Radtkeite leaves yellow-orange, Cinnabar leaves scarlet.
How to tell apart: Streak differs — Radtkeite leaves yellow-orange, Calomel leaves white.
How to tell apart: Streak differs — Radtkeite leaves yellow-orange, Kadyrelite leaves yellow.
Often found alongside radtkeite
Minerals reported to co-occur with radtkeite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Hg₃S₂ClI
- Mohs hardness
- 1.5-2
- Density
- 8.8 g/cm³
- Colors
- Streak
- Yellow-orange
- Luster
- Adamantine
- Transparency
- Translucent
- Crystal system
- Trigonal
- Crystal habit
- Small Crystals, Coatings
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Mercury-bearing Hydrothermal Deposits
- Typical price
- $100-500 for small micro-mounts
Where rockhounds find radtkeite
Classic worldwide localities
- McDermitt Mine, Nevada, USA
- Cordero Mine, Nevada, USA
Field-hunting tip
Look in mercury-bearing hydrothermal deposits country — that is the host setting where radtkeite typically forms. If you start seeing cinnabar, calomel, eglestonite in float, you are in the right ground. Field specimens usually show a small crystals, coatings habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify radtkeite?+
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How much is radtkeite worth?+
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Find radtkeite on the map
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