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. Aurivilliusite leaves a dark red-brown streak.
- 3Read the lusterHold the specimen under a strong light. Aurivilliusite typically shows a metallic luster.
- 4Match the color rangeCompare against the expected color range: dark gray-black.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: tabular crystals, crusts.
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 yellowish-white; luster reads metallic on Aurivilliusite and adamantine on Eglestonite.
How to tell apart: Streak differs, so Aurivilliusite leaves dark red-brown, Terlinguaite leaves yellow; luster reads metallic on Aurivilliusite and 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
- Hg₄O₂ClI
- Mohs hardness
- 2
- Density
- 8.85 g/cm³
- Colors
- Streak
- Dark Red-brown
- Luster
- Metallic
- Transparency
- Opaque
- Crystal system
- Monoclinic
- Crystal habit
- Tabular Crystals, Crusts
- Cleavage
- Distinct On{100}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Mercury-rich Hydrothermal Deposits
Where rockhounds find aurivilliusite
Classic worldwide localities
- Krutaya Gorka, Russia
- Terlingua District, USA
Field-hunting tip
Look in mercury-rich hydrothermal deposits country, the host setting where aurivilliusite typically forms. If you start seeing cinnabar, calomel, eglestonite in float, you are in the right ground. Field specimens usually show a tabular crystals, crusts habit, so 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?+
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Find aurivilliusite on the map
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