Eudialyte

Eudialyte is a somewhat rare, nine member ring cyclosilicate mineral, which forms in alkaline igneous rocks, such as nepheline syenites. It name derives from the Greek phrase meaning “well decomposable” and alludes to its ready solubility in acid.

It was first described in 1819 for an occurrence in nepheline syenite of the Ilimaussaq intrusive complex of southwest Greenland.

This stone used as a minor ore of zirconium. Another use is as a minor gemstone, but this use limited by its rarity, which compounded by its poor crystal habit. These factors make eudialyte of primary interest as a collector’s mineral.