Oyonite is a rare, naturally occurring organic mineraloid found primarily in the coal-bearing sedimentary formations of the Oyon district in Peru. It appears as a brittle, black to dark brown massive substance that is chemically related to organic resins and coals, often recovered from fossilized plant material.

Hardness

3-4

Mohs

Luster

Dull

Streak

Brown

Transparency

Opaque

mineralrareMineraloid family

Oyonite

Hardness: 3-4
Luster: Dull
Streak: Brown
Transparency: Opaque

Is this oyonite?

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 oyonite with a known reference. Oyonite sits at Mohs 3-4, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Oyonite leaves a brown streak.
3
Read the luster
Hold the specimen under a strong light. Oyonite typically shows a dull luster.
4
Match the color range
Compare against the expected color range: black, dark brown.
5
Look at form & habit
Typical habit: massive.

Often confused with

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

sedimentary

Coal

Mohs 0.5-2.5

How to tell apart: Streak differs, so Oyonite leaves brown, Coal leaves black; luster reads dull on Oyonite and dull to submetallic on Coal.

How to tell apart: Luster reads dull on Oyonite and resinous on Jet.

Compare →

Often found alongside oyonite

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

All properties

Chemical formula: C₁₀H₁₂O
Mohs hardness: 3-4
Density: 2.2-2.5 g/cm³
Colors: Black Dark Brown
Streak: Brown
Luster: Dull
Transparency: Opaque
Crystal habit: Massive
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: Sedimentary Coal Beds
Typical price: $10-50 per specimen

Where rockhounds find oyonite

Classic worldwide localities

Oyon, Peru

Field-hunting tip

Look in sedimentary coal beds country, the host setting where oyonite typically forms. If you start seeing coal, pyrite in float, you are in the right ground. Field specimens usually show a massive habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify oyonite?+

Mohs hardness is 3-4. It typically shows a dull luster. The streak is brown. Common colors include black, dark brown.

Where is oyonite found?+

Notable localities include Oyon, Peru.

How much is oyonite worth?+

Typical asking prices fall in the range of $10-50 per specimen. Quality, size, and provenance can move individual specimens well outside that range.

What rocks look like oyonite?+

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

What minerals are found with oyonite?+

Oyonite commonly co-occurs with Coal, Pyrite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does oyonite form in?+

Oyonite typically forms in sedimentary coal beds. Working float back to the host body is the standard way to chase a fresh occurrence.

What is oyonite used for?+

Oyonite is used in collector.

Find oyonite on the map

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