Hitachiite is a rare lead-bismuth telluride-sulfide belonging to the tetradymite group. It typically occurs as small, lead-gray lamellar or granular masses within hydrothermal skarn deposits.

Hardness

1.5-2

Mohs

Luster

Metallic

Streak

Black

Transparency

Opaque

mineralrareTetradymite Group family

Hitachiite

Hitachiite is a rare lead-bismuth telluride-sulfide belonging to the tetradymite group. It typically occurs as small, lead-gray lamellar or granular masses within hydrothermal skarn deposits.

Hardness: 1.5-2
Luster: Metallic
Streak: Black
Transparency: Opaque

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Is this hitachiite?

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 hitachiite with a known reference. Hitachiite sits at Mohs 1.5-2, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Streak: black.
3
Read the luster
Hold the specimen under a strong light. Luster: metallic.
4
Match the color range
Compare against the expected color range: lead-gray, tin-white.
5
Look at form & habit
Crystal system: trigonal. Typical habit: lamellar, tabular, granular.

Often confused with

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

mineral

Tetradymite

Mohs 1.5-2

How to tell apart: Streak differs, so Hitachiite leaves black, Tetradymite leaves pale steel-gray.

How to tell apart: Streak differs, so Hitachiite leaves black, Bismuthinite leaves lead-gray.

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Often found alongside hitachiite

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

All properties

Chemical formula: Pb₅Bi₂Te₂S₆
Mohs hardness: 1.5-2
Density: 7.5 g/cm³
Colors: Lead-gray Tin-white
Streak: Black
Luster: Metallic
Transparency: Opaque
Crystal system: Trigonal
Crystal habit: Lamellar, tabular, granular
Cleavage: Perfect basal
Rarity: Rare
Uses: Collector, Scientific research
Host rock: skarn deposits

Where rockhounds find hitachiite

Classic worldwide localities

Hitachi Mine, Japan
Various hydrothermal deposits worldwide

Field-hunting tip

Where it forms: skarn deposits. If you start seeing chalcopyrite, pyrite, galena in float, you are in the right ground. Typical habit: lamellar, tabular, granular. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify hitachiite?+

Mohs hardness is 1.5-2. Luster: metallic. The streak is black. Common colors include lead-gray, tin-white.

Where is hitachiite found?+

Notable localities include Hitachi Mine, Japan; Various hydrothermal deposits worldwide.

Is hitachiite safe to handle?+

Hitachiite contains lead. Contains lead; handle with care and avoid inhalation of dust or ingestion. Wash hands thoroughly after handling specimens.

What rocks look like hitachiite?+

Hitachiite is most often confused with Tetradymite, Bismuthinite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with hitachiite?+

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

What kind of rock does hitachiite form in?+

Where it forms: skarn deposits. Working float back to the host body is the standard way to chase a fresh occurrence.

What is hitachiite used for?+

Hitachiite is used in collector, scientific research.

Find hitachiite on the map

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