Zirsilite-(Ce) is a rare cyclosilicate mineral belonging to the eudialyte group, primarily identified in alkaline igneous complexes. It usually forms as small tabular crystals or grains within pegmatitic environments associated with nepheline syenites. Due to its extreme rarity and complex chemistry, it is primarily sought after by advanced systematic mineral collectors.

Hardness

5-6

Mohs

Luster

Vitreous

Streak

White

Transparency

Translucent

mineralrareEudialyte Group family

Zirsilite-(Ce)

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

Is this zirsilite-(ce)?

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 zirsilite-(ce) with a known reference. Zirsilite-(Ce) 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. Zirsilite-(Ce) leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Zirsilite-(Ce) typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: yellow, brown.
5
Look at form & habit
Crystal system: trigonal. Typical habit: tabular crystals.

Often confused with

Zirsilite-(Ce) vs. its common look-alikes — and how to tell them apart in the field.

How to tell apart: Zircon is the harder of the two (Mohs 7.5 vs. 5-6); luster reads vitreous on Zirsilite-(Ce) and adamantine on Zircon.

Compare →

Often found alongside zirsilite-(ce)

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

All properties

Chemical formula: (Na,K)₃(Ca,Na,Ce)₃(Zr,Ti)Si₈O₂₂(OH,Cl)₂
Mohs hardness: 5-6
Density: 3.17 g/cm³
Colors: Yellow Brown
Streak: White
Luster: Vitreous
Transparency: Translucent
Crystal system: Trigonal
Crystal habit: Tabular Crystals
Cleavage: None
Rarity: Rare
Uses: Collector
Host rock: Alkaline Pegmatites
Typical price: $50-300 per specimen

Where rockhounds find zirsilite-(ce)

Classic worldwide localities

Khibiny Massif, Russia
Lovozero Massif, Russia

Field-hunting tip

Look in alkaline pegmatites country — that is the host setting where zirsilite-(ce) typically forms. If you start seeing aegirine, nepheline, microcline in float, you are in the right ground. Field specimens usually show a tabular crystals habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify zirsilite-(ce)?+

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

Where is zirsilite-(ce) found?+

Notable localities include Khibiny Massif, Russia; Lovozero Massif, Russia.

How much is zirsilite-(ce) 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 zirsilite-(ce)?+

Zirsilite-(Ce) is most often confused with Eudialyte, Zircon. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with zirsilite-(ce)?+

Zirsilite-(Ce) commonly co-occurs with Aegirine, Nepheline, Microcline, Arfvedsonite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does zirsilite-(ce) form in?+

Zirsilite-(Ce) typically forms in alkaline pegmatites. Working float back to the host body is the standard way to chase a fresh occurrence.

What is zirsilite-(ce) used for?+

Zirsilite-(Ce) is used in collector.

Find zirsilite-(ce) on the map

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