Gemstone Glossary

Eudialyte

Eudialyte is a rather rae mineral well known for its distinctive colors including: red-violet, pink, blue, yellow and an attractive brown. It was discovered in 1819 in the Julianehaab district of Greenland. The name Eudialyte is originated from the Greek ‘Eu’ for “Well” and ‘Dialytos’ for “Decomposable” for the fact that it is easily dissolved in acids.


Eudialyte is actually composed of several minerals: Sodium, Calcium, Cerium, Iron, Manganese, Zirconium, Silicon, Hydrogen and Chlorine [Na4(Ca,Ce,Fe, Mn)2ZrSi6O17(OH, Cl)2]. It ranks 5 to 5.5 on the Moh’s Scale of Hardness with a Specific Gravity of 2.9. Crystals of Eudialyte are vitreous and translucent to transparent. They are normally found embedded in the host rock, surrounded by other minerals like Nepheline, Albite, Natrolite, and Calcite as well as several other rare minerals. Eudialyte is commonly found as coarse grains, and only occasionally forms any crystal faces at all.

Eudialyte only occurs in alkali environments, especially sodium-rich ones. Its notable occurrences include: Mont Saint-Hilaire, Quebec, Canada; Julianehaab, Greenland; Madagascar and Magnet Cove, Arkansas, USA. However, most of the Eudialyte on the market today comes from the Kola Peninsula of Russia.

The Kola Peninsula in northwestern Russia is a region that has produced over three hundred different mineral species and is the type locality for over a hundred minerals. Eudialyte is an example of an unusual mineral that comes from these mineral unique sites. Not only is it rich in sodium, but has zirconium, cerium and often traces of yttrium in its structure.

Eudialyte’s attractivness and distinctive colors have made it popular among mineral collectors. However, due to the lack of good crystal form, it is rarely cut as a gemstone.