Aurivilliusite is a rare mercury oxyhalide mineral often found as small, yellow, tabular crystals or coatings. It is primarily identified by its extreme density and association with other secondary mercury minerals in oxidation zones of mercury deposits.
Is this aurivilliusite?
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 aurivilliusite with a known reference. Aurivilliusite 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: dark red-brown.
- 3Read the lusterHold the specimen under a strong light. Luster: metallic.
- 4Match the color rangeCompare against the expected color range: dark gray black.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: encrustations.
Often confused with
Aurivilliusite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Aurivilliusite leaves dark red-brown, Eglestonite leaves yellow or greenish yellow, rapidly becoming black; luster reads metallic on Aurivilliusite and brilliant adamantine to resinous on Eglestonite.
How to tell apart: Streak differs, so Aurivilliusite leaves dark red-brown, Terlinguaite leaves lemon-yellow, turning olive-green; luster reads metallic on Aurivilliusite and brilliant adamantine on Terlinguaite.
Often found alongside aurivilliusite
Minerals reported to co-occur with aurivilliusite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- HgHgOI
- Mohs hardness
- 2
- Density
- 8.96 g/cm³
- Colors
- Dark gray black
- Streak
- Dark red-brown
- Luster
- Metallic
- Transparency
- Opaque
- Crystal system
- Monoclinic
- Crystal habit
- Encrustations
- Cleavage
- Distinct on{100}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- A rare mineral of uncertain paragenesis in a suite of Hg-bearing oxy-halide phases
Where rockhounds find aurivilliusite
Classic worldwide localities
- A small prospect pit near the long-abandoned Clear Creek mercury mine, New Idria district, San Benito County, California, USA (type locality)
Field-hunting tip
Where it forms: A rare mineral of uncertain paragenesis in a suite of Hg-bearing oxy-halide phases. If you start seeing native mercury, cinnabar, edgarbaileyite in float, you are in the right ground. Typical habit: encrustations. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify aurivilliusite?+
Where is aurivilliusite found?+
Is aurivilliusite safe to handle?+
What rocks look like aurivilliusite?+
What minerals are found with aurivilliusite?+
What kind of rock does aurivilliusite form in?+
What is aurivilliusite used for?+
Find aurivilliusite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
