Coloradoite is a rare mercury telluride mineral often found in association with gold and silver deposits. It typically appears as massive, dark grey metallic grains that lack visible cleavage, and it is most famous for its occurrences in tellurium-rich epithermal vein systems.

Hardness

2.5

Mohs

Luster

Metallic

Streak

Black

Transparency

Opaque

mineralrare

Coloradoite

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

Is this coloradoite?

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 coloradoite with a known reference. Coloradoite 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. Coloradoite leaves a black streak.
3
Read the luster
Hold the specimen under a strong light. Coloradoite typically shows a metallic luster.
4
Match the color range
Compare against the expected color range: dark gray, black.
5
Look at form & habit
Crystal system: cubic. Typical habit: massive, granular, or rarely as tetrahedral crystals.

Often confused with

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

mineral

Galena

Mohs 2.5

How to tell apart: Streak differs — Coloradoite leaves black, Galena leaves lead-gray.

Often found alongside coloradoite

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

All properties

Chemical formula: HgTe
Mohs hardness: 2.5
Density: 8.1-8.2 g/cm³
Colors: Dark Gray Black
Streak: Black
Luster: Metallic
Transparency: Opaque
Crystal system: Cubic
Crystal habit: Massive, Granular, Or Rarely as Tetrahedral Crystals
Cleavage: None
Rarity: Rare
Uses: Collector, Research
Host rock: Epithermal Gold-telluride Veins
Typical price: $50-500 depending on specimen size and association

Where rockhounds find coloradoite

Classic worldwide localities

Boulder County, Colorado, USA
Kalgoorlie, Western Australia
Nagyág, Romania
Taimyr Peninsula, Russia

Field-hunting tip

Look in epithermal gold-telluride veins country — that is the host setting where coloradoite typically forms. If you start seeing gold, tellurium, pyrite in float, you are in the right ground. Field specimens usually show a massive, granular, or rarely as tetrahedral crystals habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify coloradoite?+

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

Where is coloradoite found?+

Notable localities include Boulder County, Colorado, USA; Kalgoorlie, Western Australia; Nagyág, Romania; Taimyr Peninsula, Russia.

How much is coloradoite worth?+

Typical asking prices fall in the range of $50-500 depending on specimen size and association. Quality, size, and provenance can move individual specimens well outside that range.

Is coloradoite safe to handle?+

It contains toxic constituents. Contains mercury and tellurium. Collectors should wear gloves when handling, avoid inhaling dust, and wash hands thoroughly after contact. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like coloradoite?+

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

What minerals are found with coloradoite?+

Coloradoite commonly co-occurs with Gold, Tellurium, Pyrite, Sylvanite, Quartz. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does coloradoite form in?+

Coloradoite typically forms in epithermal gold-telluride veins. Working float back to the host body is the standard way to chase a fresh occurrence.

What is coloradoite used for?+

Coloradoite is used in collector, research.

Find coloradoite on the map

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