Selenostephanite is a rare selenium-rich variety of the silver sulfosalt stephanite. It typically occurs as small, metallic black crystals in hydrothermal vein environments and is primarily sought after by advanced collectors of silver minerals.
Is this selenostephanite?
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 selenostephanite with a known reference. Selenostephanite sits at Mohs 2.5-3, 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: metallic.
- 4Match the color rangeCompare against the expected color range: lead gray.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: aggregates, platy.
Often confused with
Selenostephanite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Selenostephanite leaves black, Stephanite leaves iron-black.
How to tell apart: Streak differs, so Selenostephanite leaves black, Pyrargyrite leaves purplish red; luster reads metallic on Selenostephanite and adamantine on Pyrargyrite.
Often found alongside selenostephanite
Minerals reported to co-occur with selenostephanite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Ag₅SbSe₄
- Mohs hardness
- 2.5-3
- Density
- 7.5 g/cm³
- Colors
- Streak
- Black
- Luster
- Metallic
- Transparency
- Opaque
- Crystal system
- Orthorhombic
- Crystal habit
- Aggregates, platy
- Cleavage
- Imperfect
- Rarity
- Rare
- Uses
- Collector, Mineralogical study
- Host rock
- In quartz and orthoclase-quartz veins with other silver minerals in a volcanogenic Au–Ag deposit
Where rockhounds find selenostephanite
Classic worldwide localities
- Rudnaya Sopka Au–Ag deposit, central Chukotka Peninsula, Russia (type locality)
Field-hunting tip
Where it forms: In quartz and orthoclase-quartz veins with other silver minerals in a volcanogenic Au–Ag deposit. If you start seeing miaragyrite, clausthalite, au–ag alloy in float, you are in the right ground. Typical habit: aggregates, platy. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify selenostephanite?+
Where is selenostephanite found?+
Is selenostephanite safe to handle?+
What rocks look like selenostephanite?+
What minerals are found with selenostephanite?+
What kind of rock does selenostephanite form in?+
What is selenostephanite used for?+
Find selenostephanite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
