Argyrodite is a rare silver germanium sulfide primarily known for being the mineral in which the element germanium was first discovered. It typically occurs as opaque, metallic crystals in hydrothermal veins and is highly prized by collectors for its association with rare silver species.
Is this argyrodite?
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 argyrodite with a known reference. Argyrodite 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: gray-black.
- 3Read the lusterHold the specimen under a strong light. Luster: strong metallic.
- 4Match the color rangeCompare against the expected color range: black, steel gray.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: massive, subhedral crystals.
Often confused with
Argyrodite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Argyrodite leaves gray-black, Stephanite leaves iron-black; luster reads strong metallic on Argyrodite and metallic on Stephanite.
How to tell apart: Streak differs, so Argyrodite leaves gray-black, Polybasite leaves black; luster reads strong metallic on Argyrodite and metallic on Polybasite.
How to tell apart: Luster reads strong metallic on Argyrodite and metallic on Canfieldite.
Often found alongside argyrodite
Minerals reported to co-occur with argyrodite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Ag₈GeS₆
- Mohs hardness
- 2.5-3
- Density
- 6.29 g/cm³
- Colors
- Streak
- Gray-black
- Luster
- Strong metallic
- Transparency
- Opaque
- Crystal system
- Orthorhombic
- Crystal habit
- Massive, subhedral crystals
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector, Scientific research
- Host rock
- In low-temperature polymetallic deposits with silver sulfosalts (Freiberg, Germany); in high-temperature Sn–Ag deposits (Bolivia)
Where rockhounds find argyrodite
Classic worldwide localities
- Rico, Dolores Co., Colorado, USA
- Saxony, from the Himmelsfürst (type locality) and other mines, Erbisdorf, near Freiberg, Germany
- Fournial mine, Massiac region, Cantal, France
- Vale das Gatas tungsten mine, near Vila Real, northern Portugal
- Silvermines, Co. Tipperary, Ireland
- A number of localities in Bolivia, including Aullagas, Colquechaca, Potosí, Oruro, Porco, Chocaya, and Machacamarca
Field-hunting tip
Where it forms: In low-temperature polymetallic deposits with silver sulfosalts (Freiberg, Germany); in high-temperature Sn–Ag deposits (Bolivia). If you start seeing canfieldite, stephanite, acanthite in float, you are in the right ground. Typical habit: massive, subhedral crystals. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify argyrodite?+
Where is argyrodite found?+
Is argyrodite safe to handle?+
What rocks look like argyrodite?+
What minerals are found with argyrodite?+
What kind of rock does argyrodite form in?+
What is argyrodite used for?+
Find argyrodite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
