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, 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.