Ishiharaite is a rare member of the tetrahedrite group characterized by its high indium content, primarily known from the Toyoha mine in Japan. It typically appears as metallic, dark gray tetrahedral crystals associated with zinc and lead sulfides in hydrothermal deposits.

Hardness

3-4

Mohs

Luster

Metallic

Transparency

Opaque

mineralrareTetrahedrite Group family

Ishiharaite

Hardness: 3-4
Luster: Metallic
Transparency: Opaque

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Is this ishiharaite?

4-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 ishiharaite with a known reference. Ishiharaite sits at Mohs 3-4, softer than the next harder reference, harder than the previous one.
2
Read the luster
Hold the specimen under a strong light. Luster: metallic.
3
Match the color range
Compare against the expected color range: dark gray.
4
Look at form & habit
Crystal system: cubic. Typical habit: tetrahedral crystals, massive.

Often confused with

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

How to tell apart: Luster reads metallic on Ishiharaite and resinous to adamantine on Sphalerite.

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Often found alongside ishiharaite

Minerals reported to co-occur with ishiharaite. Spotting these in float or country rock is a strong cue you are in the right ground.

All properties

Chemical formula: (Cu,Ga,Fe,In,Zn)S
Mohs hardness: 3-4
Density: 4.343 g/cm³
Colors: Dark gray
Luster: Metallic
Transparency: Opaque
Crystal system: Cubic
Crystal habit: Tetrahedral crystals, massive
Rarity: Rare
Uses: Collector
Host rock: In an epithermal precious- and base-metal vein deposit

Where rockhounds find ishiharaite

Classic worldwide localities

Nueva Esperanza vein, Capillitas mine, Farallón Negro district, eastern slope of the Capillitas Range, Catamarca province, northwestern Argentina

Field-hunting tip

Where it forms: In an epithermal precious- and base-metal vein deposit. If you start seeing tennantite, chalcopyrite, sphalerite in float, you are in the right ground. Typical habit: tetrahedral crystals, massive. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify ishiharaite?+

Mohs hardness is 3-4. Luster: metallic. Common colors include dark gray.

Where is ishiharaite found?+

Notable localities include Nueva Esperanza vein, Capillitas mine, Farallón Negro district, eastern slope of the Capillitas Range, Catamarca province, northwestern Argentina.

Is ishiharaite safe to handle?+

Ishiharaite contains copper. Contains arsenic and copper; avoid inhalation of dust and wash hands thoroughly after handling.

What rocks look like ishiharaite?+

Ishiharaite is most often confused with Tetrahedrite, Tennantite, Sphalerite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with ishiharaite?+

Ishiharaite commonly co-occurs with Tennantite, Chalcopyrite, Sphalerite, Pyrite, Galena, Quartz. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does ishiharaite form in?+

Where it forms: In an epithermal precious- and base-metal vein deposit. Working float back to the host body is the standard way to chase a fresh occurrence.

What is ishiharaite used for?+

Ishiharaite is used in collector.

Find ishiharaite on the map

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