Eudialyte Value, Price, and Jewelry Information
Although cabochons could be cut from massive eudialite or translucent crystals, transparent material suitable for faceting is elusive and always small.
The International Gem Society (IGS) has a list of businesses offering gemstone appraisal services.
|Crystallography||Hexagonal (trigonal); tabular crystals, may be hexagonal or trigonal; also prismatic, rhombohedral, massive.|
|Colors||Shades of brownish red, yellowish brown, pink, red. Often translucent.|
|Luster||Vitreous; greasy; may be dull.|
|Stone Sizes||Faceted gems well under 1 carat in size have been cut from Quebec material. These are deep red and extremely rare. National Museums of Canada (Ottawa, Ontario): 0.30, 0.40 (intense red, Sheffield Lake, Quebec, Canada).|
|Formula||Na4( Ca,Fe,Ce,Mn)2ZrSi6O17(OH,CI)2 (Note: Eucolite= calcium-rich variety)|
|Pleochroism||Varies with body color.|
Optics: o= 1.591-1.623; e= 1.594-1.633.
Uniaxial (+) but sign variable (eucolite reported to be (-) with higher indices and S.G.).
Occurrence: Nepheline syenites and associated pegmatites:
Julienhaab District. Greenland: crystals up to I inch in length.
Kola Peninsula, USSR: Pilansberg. South Africa. Ampasibitika, Madagascar
Magnet Cove, Arkansas: rich red color, in feldspar.
Mt. Ste. Hilaire, Quebec, Canada: facetable (o = 1.596; e = 1.600; birefringence = 0.004).
Kipawa Complex. Sheffield Lake, Temiscamingue County,Quebec, Canada: red, facetable.
Sweden: o = 1.598; e = 1.604; Birefringence = 0.004; S.G. = 2.88.
Comments: Although cabochons could be cut from massive eudialite or translucent crystals, transparent material suitable for faceting is elusive and always small.
Name: From Greek words meaning easy to dissolve because of its easy solubility in acids.