Donharrisite is an extremely rare mercury-nickel sulfide found primarily in the mercury mining districts of Texas. It typically occurs as microscopic anhedral grains associated with other rare mercury minerals and is prized by advanced mineral collectors for its unique chemistry.
Is this donharrisite?
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 donharrisite with a known reference. Donharrisite sits at Mohs ~2, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: brownish gray.
- 3Read the lusterHold the specimen under a strong light. Luster: metallic.
- 4Match the color rangeCompare against the expected color range: brown.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: micaceous, microscopic crystals.
Often confused with
Donharrisite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Donharrisite leaves brownish gray, Cinnabar leaves scarlet; luster reads metallic on Donharrisite and adamantine, inclining to metallic when dark; dull in friable material on Cinnabar.
How to tell apart: Streak differs, so Donharrisite leaves brownish gray, Coloradoite leaves black; luster reads metallic on Donharrisite and bright metallic on Coloradoite.
Often found alongside donharrisite
Minerals reported to co-occur with donharrisite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Ni₃HgS₃
- Mohs hardness
- ~2
- Density
- 5.18 g/cm³
- Colors
- Streak
- Brownish gray
- Luster
- Metallic
- Transparency
- Opaque
- Crystal system
- Monoclinic
- Crystal habit
- Micaceous, microscopic crystals
- Cleavage
- Perfect on {001}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- On an old museum specimen from a polymetallic Hg–Pb-rich dolostone stratabound ore deposit
Where rockhounds find donharrisite
Classic worldwide localities
- Erasmus mine (probable), Schwarzleo district, near Leogang, Salzburg, Austria (type locality)
Field-hunting tip
Where it forms: On an old museum specimen from a polymetallic Hg–Pb-rich dolostone stratabound ore deposit. If you start seeing cinnabar, mercury, polydymite in float, you are in the right ground. Typical habit: micaceous, microscopic crystals. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify donharrisite?+
Where is donharrisite found?+
Is donharrisite safe to handle?+
What rocks look like donharrisite?+
What minerals are found with donharrisite?+
What kind of rock does donharrisite form in?+
What is donharrisite used for?+
Find donharrisite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
