Dunite is an ultramafic plutonic rock composed almost entirely of olivine. It is typically found in ophiolite complexes and often shows significant alteration into serpentinite, making fresh, solid samples a prized find for rockhounders interested in mantle petrology.

Hardness

6.5-7

Mohs

Luster

Vitreous

Streak

White

Transparency

Translucent

igneouscommonOlivine Group family

Dunite

Hardness: 6.5-7
Luster: Vitreous
Streak: White
Transparency: Translucent

Is this dunite?

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 dunite with a known reference. Dunite sits at Mohs 6.5-7, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Dunite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Dunite typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: yellow-green, olive-green, dark green.
5
Look at form & habit
Typical habit: massive.

Often confused with

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

igneous

Peridotite

Mohs 6-7

How to tell apart: Luster reads vitreous on Dunite and vitreous to dull on Peridotite.

How to tell apart: Dunite is noticeably harder (Mohs 6.5-7 vs. 2.5-5.5); luster reads vitreous on Dunite and waxy on Serpentinite.

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Often found alongside dunite

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

All properties

Mohs hardness: 6.5-7
Density: 3.2-3.4 g/cm³
Colors: Yellow-green Olive-green Dark Green
Streak: White
Luster: Vitreous
Transparency: Translucent
Crystal habit: Massive
Cleavage: None
Rarity: Common
Uses: Industrial, Collector, Geological Study
Host rock: Mantle Rocks
Typical price: $5-30 specimen

Where rockhounds find dunite

Classic worldwide localities

Dun Mountain, New Zealand
Twin Sisters Mountains, USA
Troodos Ophiolite, Cyprus
Norway
Canada

Field-hunting tip

Look in mantle rocks country, the host setting where dunite typically forms. If you start seeing olivine, chromite, pyroxene 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 dunite?+

Mohs hardness is 6.5-7. It typically shows a vitreous luster. The streak is white. Common colors include yellow-green, olive-green, dark green.

Where is dunite found?+

Notable localities include Dun Mountain, New Zealand; Twin Sisters Mountains, USA; Troodos Ophiolite, Cyprus; Norway; Canada.

How much is dunite worth?+

Typical asking prices fall in the range of $5-30 specimen. Quality, size, and provenance can move individual specimens well outside that range.

What rocks look like dunite?+

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

What minerals are found with dunite?+

Dunite commonly co-occurs with Olivine, Chromite, Pyroxene, Magnetite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does dunite form in?+

Dunite typically forms in mantle rocks. Working float back to the host body is the standard way to chase a fresh occurrence.

What is dunite used for?+

Dunite is used in industrial, collector, geological study.

Find dunite on the map

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