Cancrisilite is a rare member of the cancrinite group, often found within alkaline intrusive complexes. It is chemically distinguished by its carbonate-rich composition and is typically identified by its hexagonal habit and association with other feldspathoid minerals.

Hardness

5-6

Mohs

Luster

Vitreous

Streak

White

Transparency

Transparent

mineralrareCancrinite Group family

Cancrisilite

Hardness: 5-6
Luster: Vitreous
Streak: White
Transparency: Transparent

Is this cancrisilite?

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 cancrisilite with a known reference. Cancrisilite sits at Mohs 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. Cancrisilite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Cancrisilite typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: colorless, white, gray.
5
Look at form & habit
Crystal system: hexagonal. Typical habit: prismatic crystals.

Often confused with

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

Often found alongside cancrisilite

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

All properties

Chemical formula: Na₈(Al₆Si₆O₂₄)(CO₃)·2H₂O
Mohs hardness: 5-6
Density: 2.44 g/cm³
Colors: Colorless White Gray
Streak: White
Luster: Vitreous
Transparency: Transparent
Crystal system: Hexagonal
Crystal habit: Prismatic Crystals
Cleavage: Perfect
Rarity: Rare
Uses: Collector
Host rock: Alkaline Igneous Rocks
Typical price: $50-300 per specimen

Where rockhounds find cancrisilite

Classic worldwide localities

Kola Peninsula, Russia
Mont Saint-Hilaire, Canada

Field-hunting tip

Look in alkaline igneous rocks country, the host setting where cancrisilite typically forms. If you start seeing nepheline, sodalite, microcline in float, you are in the right ground. Field specimens usually show a prismatic crystals habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify cancrisilite?+

Mohs hardness is 5-6. It typically shows a vitreous luster. The streak is white. Common colors include colorless, white, gray.

Where is cancrisilite found?+

Notable localities include Kola Peninsula, Russia; Mont Saint-Hilaire, Canada.

How much is cancrisilite worth?+

Typical asking prices fall in the range of $50-300 per specimen. Quality, size, and provenance can move individual specimens well outside that range.

What rocks look like cancrisilite?+

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

What minerals are found with cancrisilite?+

Cancrisilite commonly co-occurs with Nepheline, Sodalite, Microcline, Aegirine. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does cancrisilite form in?+

Cancrisilite typically forms in alkaline igneous rocks. Working float back to the host body is the standard way to chase a fresh occurrence.

What is cancrisilite used for?+

Cancrisilite is used in collector.

Find cancrisilite on the map

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