Pigeonite is a calcium-poor clinopyroxene that is characteristic of rapidly cooled mafic igneous rocks. It is most easily identified in thin section due to its unique optical properties, though in hand samples, it typically appears as brownish-green to black massive grains within basaltic or diabasic matrices.

Hardness

5.5-6

Mohs

Luster

Vitreous

Streak

White

Transparency

Translucent

mineralcommonPyroxene Group family

Pigeonite

Hardness: 5.5-6
Luster: Vitreous
Streak: White
Transparency: Translucent

Is this pigeonite?

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 pigeonite with a known reference. Pigeonite sits at Mohs 5.5-6 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Pigeonite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Pigeonite typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: brown, brownish-green, black.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: prismatic crystals, massive, granular.

Often confused with

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

mineral

Augite

Mohs 5.5-6

How to tell apart: Streak differs — Pigeonite leaves white, Augite leaves grayish white.

Often found alongside pigeonite

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

All properties

Chemical formula: (Ca,Mg,Fe)₂(Mg,Fe)Si₂O₆
Mohs hardness: 5.5-6
Density: 3.3-3.5 g/cm³
Colors: Brown Brownish-green Black
Streak: White
Luster: Vitreous
Transparency: Translucent
Crystal system: Monoclinic
Crystal habit: Prismatic Crystals, Massive, Granular
Cleavage: Good in 2 Directions At Nearly 90 Degrees
Rarity: Common
Uses: Collector, Scientific Research
Host rock: Mafic Igneous Rocks Such as Basalt, Diabase, And Gabbro
Typical price: $5-30 per specimen

Where rockhounds find pigeonite

Classic worldwide localities

Pigeon Point, Minnesota, USA
Bushveld Complex, South Africa
Isle of Skye, Scotland
Lunar basalt samples
Dolerite sills globally

Field-hunting tip

Look in mafic igneous rocks such as basalt, diabase, and gabbro country — that is the host setting where pigeonite typically forms. If you start seeing plagioclase, augite, olivine in float, you are in the right ground. Field specimens usually show a prismatic crystals, massive, granular habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify pigeonite?+

Mohs hardness is 5.5-6. It typically shows a vitreous luster. The streak is white. Common colors include brown, brownish-green, black.

Where is pigeonite found?+

Notable localities include Pigeon Point, Minnesota, USA; Bushveld Complex, South Africa; Isle of Skye, Scotland; Lunar basalt samples; Dolerite sills globally.

How much is pigeonite worth?+

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

What rocks look like pigeonite?+

Pigeonite is most often confused with Augite, Enstatite, Diopside. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with pigeonite?+

Pigeonite commonly co-occurs with Plagioclase, Augite, Olivine, Magnetite, Ilmenite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does pigeonite form in?+

Pigeonite typically forms in mafic igneous rocks such as basalt, diabase, and gabbro. Working float back to the host body is the standard way to chase a fresh occurrence.

What is pigeonite used for?+

Pigeonite is used in collector, scientific research.

Find pigeonite on the map

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