Eudialyte

Eudialyte

By Tim Matthews, JD, FGA, GG, DGA,
CEO and President of JTV (retired)
Published: June 2014
Modified: May 2023
Eudialyte Polished Eudialyte Rough Eudialyte Jewelry

Discovered 1819 in Greenland, this gemstone is usually found in massive forms in host rocks. Eudialyte is an extremely rare and complex mineral that occurs in red-violets, pinks, blues, yellows and browns. Well-formed crystals are rare, and opaque material is often fashioned in cabochons.

General Information

Common Name
Eudialyte
Species
Eudialyte
Transparency
Translucent - Opaque
Dispersion
Strength: None
Refractive Index
1.591-1.633
Birefringence
0.003-0.01
Optic Character
Uniaxial
Optic Sign
Positive
Polariscope Reaction
Aggregate (AGG), Doubly Refractive (DR)
Fluorescence
SWUV: Inert
LWUV: Inert
Pleochroism
Unobservable
Hardness
5-5.5
Streak
White To Pale Pink
Specific Gravity
2.740-3.000
Toughness
Poor
Luster
Vitreous, Dull
Stability
Poor
Fracture
Uneven
Cleavage
Perfect, in one direction, Poor, in one direction
Chemical Formula
Na4(Ca,Ce)2(Fe,Mn,Y)ZrSi8O22(OH,Cl)2
Crystal System
Trigonal
Chemistry Classification
Silicate

Eudialyte Colors

  • Blue Eudialyte
    Blue
  • Brown Eudialyte
    Brown
  • Multi-color Eudialyte
    Multi-color
  • Orange Eudialyte
    Orange
  • Pink Eudialyte
    Pink
  • Purple Eudialyte
    Purple
  • Red Eudialyte
    Red
  • Red Eudialyte
    Red
  • Yellow Eudialyte
    Yellow

Countries of Origin

Tanzania, United Republic Of; Russian Federation; Angola; Czechia; Guinea; United States of America; Egypt; Madagascar; Kazakhstan; Paraguay; United Kingdom of Great Britain and Northern Ireland; Libya; Portugal; Mongolia; Sweden; Mozambique; Morocco; Unknown; Malawi; Mali; China; Ireland; Saint Helena, Ascension and Tristan da Cunha; Brazil; Poland; Algeria; Cabo Verde; France; Romania; Hungary; Ukraine; Kenya; India; Spain; Canada; Norway; Namibia; Congo (the Democratic Republic of the); South Africa; Antarctica; Australia; Greenland; Tajikistan