Glaucodot is a rare cobalt-iron sulfarsenide that is frequently confused with arsenopyrite and cobaltite due to its similar metallic appearance. It is typically found in hydrothermal veins associated with other cobalt minerals and is notable for its silver-white to tin-white color that may tarnish to a dull gray.

Hardness

Mohs

Luster

Metallic

Streak

Black

Transparency

Opaque

mineralrareArsenopyrite Group family

Glaucodot

Hardness: 5
Luster: Metallic
Streak: Black
Transparency: Opaque

Is this glaucodot?

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 glaucodot with a known reference. Glaucodot sits at Mohs 5 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Glaucodot leaves a black streak.
3
Read the luster
Hold the specimen under a strong light. Glaucodot typically shows a metallic luster.
4
Match the color range
Compare against the expected color range: tin-white, silver-white, gray.
5
Look at form & habit
Crystal system: orthorhombic. Typical habit: prismatic crystals, massive, granular.

Often confused with

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

How to tell apart: Streak differs — Glaucodot leaves black, Cobaltite leaves greyish-black.

Often found alongside glaucodot

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

All properties

Chemical formula: (Co,Fe)AsS
Mohs hardness: 5
Density: 5.99-6.03 g/cm³
Colors: Tin-white Silver-white Gray
Streak: Black
Luster: Metallic
Transparency: Opaque
Crystal system: Orthorhombic
Crystal habit: Prismatic Crystals, Massive, Granular
Cleavage: Distinct On {110}
Rarity: Rare
Uses: Collector
Host rock: Hydrothermal Veins, Contact Metamorphic Deposits
Typical price: $20-150 thumbnail, $200-500 cabinet specimen

Where rockhounds find glaucodot

Classic worldwide localities

Huallapa, Peru
Tunaberg, Sweden
Hakansboda, Sweden
Schneeberg, Germany
Ouro Preto, Brazil

Field-hunting tip

Look in hydrothermal veins, contact metamorphic deposits country — that is the host setting where glaucodot typically forms. If you start seeing cobaltite, arsenopyrite, chalcopyrite in float, you are in the right ground. Field specimens usually show a prismatic crystals, massive, granular habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify glaucodot?+

Mohs hardness is 5. It typically shows a metallic luster. The streak is black. Common colors include tin-white, silver-white, gray.

Where is glaucodot found?+

Notable localities include Huallapa, Peru; Tunaberg, Sweden; Hakansboda, Sweden; Schneeberg, Germany; Ouro Preto, Brazil.

How much is glaucodot worth?+

Typical asking prices fall in the range of $20-150 thumbnail, $200-500 cabinet specimen. Quality, size, and provenance can move individual specimens well outside that range.

Is glaucodot safe to handle?+

It contains toxic constituents. Contains arsenic. Handle with care, wash hands after handling, avoid creating dust, and keep away from children and food preparation areas. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like glaucodot?+

Glaucodot is most often confused with Arsenopyrite, Cobaltite, Skutterudite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with glaucodot?+

Glaucodot commonly co-occurs with Cobaltite, Arsenopyrite, Chalcopyrite, Pyrrhotite, Bismuth. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does glaucodot form in?+

Glaucodot typically forms in hydrothermal veins, contact metamorphic deposits. Working float back to the host body is the standard way to chase a fresh occurrence.

What is glaucodot used for?+

Glaucodot is used in collector.

Find glaucodot on the map

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