Jordisite is an amorphous, molybdenum-rich mineral typically found as sooty or powdery black coatings in hydrothermal deposits. It is essentially an amorphous polymorph of molybdenite and is rarely found in crystalline form, making it a challenging but interesting specimen for collectors.
Is this jordisite?
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 jordisite with a known reference. Jordisite sits at Mohs 1-2, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: black.
- 3Read the lusterHold the specimen under a strong light. Luster: submetallic, dull.
- 4Match the color rangeCompare against the expected color range: black, blue gray.
- 5Look at form & habitCrystal system: amorphous. Typical habit: sooty, powdery, or earthy masses.
Often confused with
Jordisite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside jordisite
Minerals reported to co-occur with jordisite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- MoS₂
- Mohs hardness
- 1-2
- Density
- 4.7-4.8 g/cm³
- Streak
- Black
- Luster
- Submetallic, dull
- Transparency
- Opaque
- Crystal system
- Amorphous
- Crystal habit
- Sooty, powdery, or earthy masses
- Cleavage
- Indistinct
- Rarity
- Rare
- Uses
- Collector, Geological study
- Host rock
- As veinlets and coatings of probable medium- to low-temperature hydrothermal origin
Where rockhounds find jordisite
Classic worldwide localities
- Sun Valley mine, east of Jacob Lake, Coconino Co., Arizona, USA
- Kiggins mercury mine on the Oak fork of the Clackamas River, about 80 km southeast of Portland, Clackamas Co., Oregon, USA
- Ambrosia Lake, McKinley Co., New Mexico, USA
- Schwalder mine, Ralston Creek district, Jefferson Co., and near Lake Como, Hinsdale Co., Colorado, USA
- Himmelsfürst mine, Erbisdorf, near Freiberg, Saxony (type locality), Germany
- Bleiberg, Carinthia, Austria
Field-hunting tip
Where it forms: As veinlets and coatings of probable medium- to low-temperature hydrothermal origin. If you start seeing ilsemannite, molybdenite, uraninite in float, you are in the right ground. Typical habit: sooty, powdery, or earthy masses. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify jordisite?+
Where is jordisite found?+
What rocks look like jordisite?+
What minerals are found with jordisite?+
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Find jordisite on the map
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