Eudialyte is a complex cyclosilicate known for its striking red or pink coloration and its association with rare alkaline rocks. Collectors prize it for its well-formed rhombohedral crystals, though it is frequently found in massive, granular, or anhedral forms within igneous complexes.

Hardness

5-6

Mohs

Luster

Vitreous

Streak

White

Transparency

Translucent

mineraluncommon

Eudialyte

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

Is this eudialyte?

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 eudialyte with a known reference. Eudialyte 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. Eudialyte leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Eudialyte typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: red, pink, brown, yellow, colorless.
5
Look at form & habit
Crystal system: trigonal. Typical habit: tabular to rhombohedral crystals, massive.

Often confused with

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

Often found alongside eudialyte

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

All properties

Chemical formula: Na₁₅Ca₆(Fe²⁺,Mn)₃Zr₃SiO(O,OH,H₂O)₃(Si₃O₉)₂(Si₉O₂₇)₂(OH,Cl)₂
Mohs hardness: 5-6
Density: 2.7-3.1 g/cm³
Colors: Red Pink Brown Yellow Colorless
Streak: White
Luster: Vitreous
Transparency: Translucent
Crystal system: Trigonal
Crystal habit: Tabular to Rhombohedral Crystals, Massive
Cleavage: Poor
Rarity: Uncommon
Uses: Collector, Lapidary
Host rock: Alkaline Igneous Rocks, Nepheline Syenites, Pegmatites
Typical price: $20-150 thumbnail, $200-800 cabinet specimen

Where rockhounds find eudialyte

1 mapped spots

Classic worldwide localities

Kola Peninsula, Russia
Mont Saint-Hilaire, Canada
Greenland
Norway
Arkansas, USA

Field-hunting tip

Look in alkaline igneous rocks, nepheline syenites, pegmatites country — that is the host setting where eudialyte typically forms. If you start seeing nepheline, aegirine, microcline in float, you are in the right ground. Field specimens usually show a tabular to rhombohedral crystals, massive habit, so train your eye for that shape before scanning the outcrop. In the U.S., the densest reported localities are in Arkansas — start trip planning there.

Browse 1 U.S. spots for eudialyte →

Common questions

How do you identify eudialyte?+

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

Where is eudialyte found?+

Notable localities include Kola Peninsula, Russia; Mont Saint-Hilaire, Canada; Greenland; Norway; Arkansas, USA.

Can I find eudialyte in the United States?+

RockHoundR maps 1 eudialyte rockhounding spots across 1 U.S. states — the top states are Arkansas.

How much is eudialyte worth?+

Typical asking prices fall in the range of $20-150 thumbnail, $200-800 cabinet specimen. Quality, size, and provenance can move individual specimens well outside that range.

Is eudialyte safe to handle?+

This mineral is radioactive. Eudialyte often contains trace amounts of thorium and rare earth elements, making it weakly radioactive; handle with care and wash hands after handling. Handle with care, avoid grinding or breathing dust, and store separately.

What rocks look like eudialyte?+

Eudialyte is most often confused with Garnet, Wadeite, Catapleiite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with eudialyte?+

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

What kind of rock does eudialyte form in?+

Eudialyte typically forms in alkaline igneous rocks, nepheline syenites, pegmatites. Working float back to the host body is the standard way to chase a fresh occurrence.

What is eudialyte used for?+

Eudialyte is used in collector, lapidary.

Find eudialyte on the map

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