Crichtonite is a rare titanium-rich mineral typically found as small, sharp, black rhombohedral crystals in alpine-type veins. Collectors prize it for its perfect geometry and it is often associated with other rare titanium species like brookite and anatase.

Hardness

4.5-5

Mohs

Luster

Metallic, dull to bright

Streak

Dark gray

Transparency

Opaque

mineralrareCrichtonite Group family

Crichtonite

Hardness: 4.5-5
Luster: Metallic, dull to bright
Streak: Dark gray
Transparency: Opaque

Is this crichtonite?

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 crichtonite with a known reference. Crichtonite sits at Mohs 4.5-5, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Streak: dark gray.
3
Read the luster
Hold the specimen under a strong light. Luster: metallic, dull to bright.
4
Match the color range
Compare against the expected color range: black.
5
Look at form & habit
Crystal system: trigonal. Typical habit: rhombohedral crystals.

Often confused with

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

mineral

Ilmenite

Mohs 5-6

How to tell apart: Streak differs, so Crichtonite leaves dark gray, Ilmenite leaves black to reddish brown.

How to tell apart: Streak differs, so Crichtonite leaves dark gray, Hematite leaves cherry-red or reddish brown.

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Often found alongside crichtonite

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

All properties

Chemical formula: Sr(Mn,Y,U)Fe₂(Ti,Fe,Cr,V)₁₈(O,OH)₃₈
Mohs hardness: 4.5-5
Density: 4.46 g/cm³
Colors: Black
Streak: Dark gray
Luster: Metallic, dull to bright
Transparency: Opaque
Crystal system: Trigonal
Crystal habit: Rhombohedral crystals
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: In alpine-type fissure veins

Where rockhounds find crichtonite

Classic worldwide localities

St. Christophe, Bourg d’Oisans, Isère, France
Selva, Tavetsch, Graubünden and Wannigletscher, Binntal, Valais, Switzerland
Khibiny massif, Kola Peninsula, Russia
Fazenda Guariba, 40 km south of Diamantina, Minas Gerais, Brazil

Field-hunting tip

Where it forms: In alpine-type fissure veins. If you start seeing quartz, chlorite in float, you are in the right ground. Typical habit: rhombohedral crystals. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify crichtonite?+

Mohs hardness is 4.5-5. Luster: metallic, dull to bright. The streak is dark gray. Common colors include black.

Where is crichtonite found?+

Notable localities include St. Christophe, Bourg d’Oisans, Isère, France; Selva, Tavetsch, Graubünden and Wannigletscher, Binntal, Valais, Switzerland; Khibiny massif, Kola Peninsula, Russia; Fazenda Guariba, 40 km south of Diamantina, Minas Gerais, Brazil.

Is crichtonite safe to handle?+

Crichtonite contains uranium or thorium and vanadium and calls for real care. Wash your hands afterwards, never grind or breathe the dust, and store it apart from specimens you handle often.

What rocks look like crichtonite?+

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

What minerals are found with crichtonite?+

Crichtonite commonly co-occurs with Quartz, Chlorite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does crichtonite form in?+

Where it forms: In alpine-type fissure veins. Working float back to the host body is the standard way to chase a fresh occurrence.

What is crichtonite used for?+

Crichtonite is used in collector.

Find crichtonite on the map

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