Lindsleyite is a rare strontium-bearing member of the crichtonite group found as inclusions in diamonds or associated with kimberlitic heavy mineral concentrates. It is typically identified by its dark, submetallic appearance and its specific geochemical signature found in mantle-derived xenoliths.

Hardness

6-7

Mohs

Luster

Submetallic

Streak

Black

Transparency

Opaque

mineralrareCrichtonite Group family

Lindsleyite

Hardness: 6-7
Luster: Submetallic
Streak: Black
Transparency: Opaque

Is this lindsleyite?

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 lindsleyite with a known reference. Lindsleyite sits at Mohs 6-7 — softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Lindsleyite leaves a black streak.
3
Read the luster
Hold the specimen under a strong light. Lindsleyite typically shows a submetallic luster.
4
Match the color range
Compare against the expected color range: black.
5
Look at form & habit
Crystal system: trigonal. Typical habit: subhedral to euhedral tabular crystals.

Often confused with

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

How to tell apart: Streak differs — Lindsleyite leaves black, Mathiasite leaves brownish black.

How to tell apart: Luster reads submetallic on Lindsleyite and metallic on Loveringite.

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Often found alongside lindsleyite

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

All properties

Chemical formula: (Sr,Ba)(Ti,Fe,Cr,Mg)₂₁O₃₈
Mohs hardness: 6-7
Density: 4.7-4.8 g/cm³
Colors: Black
Streak: Black
Luster: Submetallic
Transparency: Opaque
Crystal system: Trigonal
Crystal habit: Subhedral to Euhedral Tabular Crystals
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: Kimberlite Pipes
Typical price: $100-500 thumbnail

Where rockhounds find lindsleyite

Classic worldwide localities

Bultfontein mine, South Africa
Koffiefontein mine, South Africa

Field-hunting tip

Look in kimberlite pipes country — that is the host setting where lindsleyite typically forms. If you start seeing chromite, phlogopite, enstatite in float, you are in the right ground. Field specimens usually show a subhedral to euhedral tabular crystals habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify lindsleyite?+

Mohs hardness is 6-7. It typically shows a submetallic luster. The streak is black. Common colors include black.

Where is lindsleyite found?+

Notable localities include Bultfontein mine, South Africa; Koffiefontein mine, South Africa.

How much is lindsleyite worth?+

Typical asking prices fall in the range of $100-500 thumbnail. Quality, size, and provenance can move individual specimens well outside that range.

What rocks look like lindsleyite?+

Lindsleyite is most often confused with Crichtonite, Mathiasite, Loveringite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with lindsleyite?+

Lindsleyite commonly co-occurs with Chromite, Phlogopite, Enstatite, Diopside. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does lindsleyite form in?+

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

What is lindsleyite used for?+

Lindsleyite is used in collector.

Find lindsleyite on the map

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