Kimberlite is a rare, potassic volcanic rock best known as the primary host rock for diamonds. It typically occurs in vertical, carrot-shaped structures known as volcanic pipes and is characterized by a porphyritic texture containing phenocrysts of olivine and phlogopite within a fine-grained matrix.

Hardness

3-5

Mohs

Luster

Dull

Streak

Gray

Transparency

Opaque

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Kimberlite

Hardness: 3-5
Luster: Dull
Streak: Gray
Transparency: Opaque

Is this kimberlite?

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

Often confused with

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

How to tell apart: Peridotite is the harder of the two (Mohs 6-7 vs. 3-5); streak differs — Kimberlite leaves gray, Peridotite leaves white; luster reads dull on Kimberlite and vitreous to dull on Peridotite.

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Often found alongside kimberlite

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

All properties

Mohs hardness: 3-5
Density: 2.6-2.9 g/cm³
Colors: Dark Gray Bluish Gray Greenish Gray Brown
Streak: Gray
Luster: Dull
Transparency: Opaque
Crystal habit: Massive
Cleavage: None
Rarity: Uncommon
Uses: Collector, Geological Study
Host rock: Volcanic Pipes
Typical price: $10-100 per specimen

Where rockhounds find kimberlite

Classic worldwide localities

Kimberley, South Africa
Yakutia, Russia
Ellendale, Australia
Ekati, Canada
Argyle, Australia

Field-hunting tip

Look in volcanic pipes country — that is the host setting where kimberlite typically forms. If you start seeing diamond, phlogopite, olivine 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 kimberlite?+

Mohs hardness is 3-5. It typically shows a dull luster. The streak is gray. Common colors include dark gray, bluish gray, greenish gray, brown.

Where is kimberlite found?+

Notable localities include Kimberley, South Africa; Yakutia, Russia; Ellendale, Australia; Ekati, Canada; Argyle, Australia.

How much is kimberlite worth?+

Typical asking prices fall in the range of $10-100 per specimen. Quality, size, and provenance can move individual specimens well outside that range.

What rocks look like kimberlite?+

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

What minerals are found with kimberlite?+

Kimberlite commonly co-occurs with Diamond, Phlogopite, Olivine, Pyrope Garnet, Diopside, Serpentine. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does kimberlite form in?+

Kimberlite typically forms in volcanic pipes. Working float back to the host body is the standard way to chase a fresh occurrence.

What is kimberlite used for?+

Kimberlite is used in collector, geological study.

Find kimberlite on the map

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