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 — 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 — that is 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.