Ourayite is a rare silver-lead-bismuth sulfosalt that typically occurs as small, lead-gray metallic grains within hydrothermal ore deposits. It is notoriously difficult to identify in the field and usually requires chemical analysis or X-ray diffraction to confirm from similar-looking gray sulfides.

Hardness

2.5

Mohs

Luster

Metallic

Streak

Black

Transparency

Opaque

mineralrare

Ourayite

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

Is this ourayite?

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 ourayite with a known reference. Ourayite 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. Ourayite leaves a black streak.
3
Read the luster
Hold the specimen under a strong light. Ourayite typically shows a metallic luster.
4
Match the color range
Compare against the expected color range: lead-gray, steel-gray.
5
Look at form & habit
Crystal system: orthorhombic. Typical habit: anhedral grains, massive, interstitial fillings.

Often confused with

Ourayite 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, so Ourayite leaves black, Galena leaves lead-gray.

How to tell apart: Streak differs, so Ourayite leaves black, Aikinite leaves lead-gray.

Often found alongside ourayite

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

All properties

Chemical formula: Ag₃Pb₄Bi₅S₁₂
Mohs hardness: 2.5
Density: 6.96 g/cm³
Colors: Lead-gray Steel-gray
Streak: Black
Luster: Metallic
Transparency: Opaque
Crystal system: Orthorhombic
Crystal habit: Anhedral Grains, Massive, Interstitial Fillings
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: Hydrothermal Veins
Typical price: $50-300 per specimen

Where rockhounds find ourayite

Classic worldwide localities

Ouray, Colorado, USA
Vaskó, Romania

Field-hunting tip

Look in hydrothermal veins country, the host setting where ourayite typically forms. If you start seeing galena, pyrite, chalcopyrite in float, you are in the right ground. Field specimens usually show a anhedral grains, massive, interstitial fillings habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify ourayite?+

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

Where is ourayite found?+

Notable localities include Ouray, Colorado, USA; Vaskó, Romania.

How much is ourayite worth?+

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

Is ourayite safe to handle?+

It contains toxic constituents. Contains lead and bismuth. Wash hands thoroughly after handling and avoid inhaling dust when trimming specimens. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like ourayite?+

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

What minerals are found with ourayite?+

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

What kind of rock does ourayite form in?+

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

What is ourayite used for?+

Ourayite is used in collector.

Find ourayite on the map

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