Koechlinite is a rare secondary bismuth molybdate mineral that typically forms as small, thin, platy crystals or earthy, micaceous coatings. It is most commonly found in the oxidation zones of bismuth-molybdenum hydrothermal deposits, often appearing as distinct yellowish scales associated with other secondary bismuth minerals.
Is this koechlinite?
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 koechlinite with a known reference. Koechlinite sits at Mohs 3 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Koechlinite leaves a yellowish-white streak.
- 3Read the lusterHold the specimen under a strong light. Koechlinite typically shows a adamantine luster.
- 4Match the color rangeCompare against the expected color range: yellow, greenish-yellow, pale yellow.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: platy crystals, micaceous masses.
Often confused with
Koechlinite vs. its common look-alikes — and how to tell them apart in the field.
How to tell apart: Streak differs — Koechlinite leaves yellowish-white, Bismutite leaves white; luster reads adamantine on Koechlinite and pearly on Bismutite.
How to tell apart: Koechlinite is noticeably harder (Mohs 3 vs. 1-2); streak differs — Koechlinite leaves yellowish-white, Molybdite leaves yellow; luster reads adamantine on Koechlinite and silky on Molybdite.
Often found alongside koechlinite
Minerals reported to co-occur with koechlinite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Bi₂MoO₆
- Mohs hardness
- 3
- Density
- 7.3-7.4 g/cm³
- Streak
- Yellowish-white
- Luster
- Adamantine
- Transparency
- Translucent
- Crystal system
- Orthorhombic
- Crystal habit
- Platy Crystals, Micaceous Masses
- Cleavage
- Perfect On {001}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Oxidized Bismuth and Molybdenum Ore Deposits
- Typical price
- $50-300 per specimen
Where rockhounds find koechlinite
Classic worldwide localities
- Schneeberg, Saxony, Germany
- Tintic District, Utah, USA
- Coro Coro, Bolivia
- Krusnoye, Russia
Field-hunting tip
Look in oxidized bismuth and molybdenum ore deposits country — that is the host setting where koechlinite typically forms. If you start seeing bismuth, bismutite, molybdenite in float, you are in the right ground. Field specimens usually show a platy crystals, micaceous masses habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify koechlinite?+
Where is koechlinite found?+
How much is koechlinite worth?+
Is koechlinite safe to handle?+
What rocks look like koechlinite?+
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Find koechlinite on the map
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