Canfieldite is a rare silver-tin sulfide that typically forms metallic black octahedral crystals. It is most frequently found in hydrothermal vein deposits alongside other silver-bearing sulfosalts and is prized primarily by advanced mineral collectors.
Is this canfieldite?
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 canfieldite with a known reference. Canfieldite sits at Mohs 2.5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: gray-black, somewhat shining.
- 3Read the lusterHold the specimen under a strong light. Luster: metallic.
- 4Match the color rangeCompare against the expected color range: black.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: botryoidal, pseudo cubic, twinning common.
Often confused with
Canfieldite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Luster reads metallic on Canfieldite and strong metallic on Argyrodite.
How to tell apart: Streak differs, so Canfieldite leaves gray-black, somewhat shining, Stephanite leaves iron-black.
How to tell apart: Streak differs, so Canfieldite leaves gray-black, somewhat shining, Acanthite leaves black.
Often found alongside canfieldite
Minerals reported to co-occur with canfieldite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Ag₈SnS₆
- Mohs hardness
- 2.5
- Density
- 6.2-6.3 g/cm³
- Colors
- Streak
- Gray-black, somewhat shining
- Luster
- Metallic
- Transparency
- Opaque
- Crystal system
- Orthorhombic
- Crystal habit
- Botryoidal, pseudo cubic, twinning common
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector, Ore of silver
- Host rock
- In polymetallic veins, formed very late in the paragenetic sequence
Where rockhounds find canfieldite
Classic worldwide localities
- Campbell mine, Bisbee, Cochise Co., Arizona, and the Leadville district, Lake Co., Colorado, USA
- Gallofa vein, Aullagas, near Colquechaca, and at the Guadaloupe mine, Chocaya, Potosí, Bolivia
- Pirquitas deposit, Riconada Department, Jujuy Province, Argentina
- Himmelsfürst mine, Erbisdorf, near Freiberg, Saxony, Germany
- Rejská, near Kutná Hora, and Příbram, Czech Republic
- Ikuno and Omidani mines, Hyogo Prefecture, and the Ashio mine, Tochigi Prefecture, Japan
Field-hunting tip
Where it forms: In polymetallic veins, formed very late in the paragenetic sequence. If you start seeing argyrodite, pyrargyrite, stephanite in float, you are in the right ground. Typical habit: botryoidal, pseudo cubic, twinning common. Train your eye for that shape before scanning the outcrop.
Common questions
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Find canfieldite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
