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.

Hardness

2.5

Mohs

Luster

Metallic

Streak

Black

Transparency

Opaque

mineralrareArgyrodite Group family

Canfieldite

Hardness: 2.5
Luster: Metallic
Streak: Black
Transparency: Opaque

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Is this canfieldite?

5-step field check

Run through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.

1
Test the hardness
Try to scratch canfieldite with a known reference. Canfieldite sits at Mohs 2.5 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Canfieldite leaves a black streak.
3
Read the luster
Hold the specimen under a strong light. Canfieldite typically shows a metallic luster.
4
Match the color range
Compare against the expected color range: black, grayish-black.
5
Look at form & habit
Crystal system: isometric. Typical habit: octahedral crystals, massive, granular.

Often confused with

Canfieldite vs. its common look-alikes — and how to tell them apart in the field.

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: 6.28 g/cm³
Colors: Black Grayish-black
Streak: Black
Luster: Metallic
Transparency: Opaque
Crystal system: Isometric
Crystal habit: Octahedral Crystals, Massive, Granular
Cleavage: None
Rarity: Rare
Uses: Collector, Ore of Silver
Host rock: Hydrothermal Veins
Typical price: $50-300 per thumbnail specimen

Where rockhounds find canfieldite

Classic worldwide localities

Colquechaca, Bolivia
Freiberg, Germany
Oruro, Bolivia
Yukon, Canada

Field-hunting tip

Look in hydrothermal veins country — that is the host setting where canfieldite typically forms. If you start seeing argyrodite, stephanite, acanthite in float, you are in the right ground. Field specimens usually show a octahedral crystals, massive, granular habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify canfieldite?+

Mohs hardness is 2.5. It typically shows a metallic luster. The streak is black. Common colors include black, grayish-black.

Where is canfieldite found?+

Notable localities include Colquechaca, Bolivia; Freiberg, Germany; Oruro, Bolivia; Yukon, Canada.

How much is canfieldite worth?+

Typical asking prices fall in the range of $50-300 per thumbnail specimen. Quality, size, and provenance can move individual specimens well outside that range.

Is canfieldite safe to handle?+

It contains toxic constituents. Contains silver and sulfur, but the potential presence of impurities and the general handling of sulfide minerals suggests washing hands after contact. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like canfieldite?+

Canfieldite is most often confused with Argyrodite, Stephanite, Acanthite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with canfieldite?+

Canfieldite commonly co-occurs with Argyrodite, Stephanite, Acanthite, Galena, Siderite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does canfieldite form in?+

Canfieldite typically forms in hydrothermal veins. Working float back to the host body is the standard way to chase a fresh occurrence.

What is canfieldite used for?+

Canfieldite is used in collector, ore of silver.

Find canfieldite on the map

RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.