Chkalovite
Na₂BeSi₂O₆
Orthorhombic. Point Group: mm2
Space Group: Fdd2    Z = 24

	Chkalovite (green) rimmed by tugtupite (red), with sodalite (orange), fluorescing under shortwave ultraviolet. Kvanefjeld. Field width 4 cm.

The beryllium sodium silicate chkalovite occurs in very coarse-grained masses to many cm across and is white to grayish-white in daylight. Its fluorescent response is variable and apparently due to other included phases. Much Ilímaussaq chkalovite does not fluoresce.

In samples from the Kvanefjeld tugtupite-in-albitite vein occurrence, chkalovite occurs as large (2-6 cm across) anhedra partially replaced by a thin (1-3 mm) rim of tugtupite. This chkalovite fluoresces pale green to bluish-green under shortwave ultraviolet.

In these specimens the closely associated tugtupite fluoresces brilliant red, creating stunning specimens.

Additional samples of chkalovite* are observed to fluoresce both greenish-blue and bluish-gray under shortwave ultraviolet. No significant response is seen under midwave or longwave ultraviolet.

*Identified by optical properties and semi-quantitative EDS.

This page edited: June 06, 2005.    SimpleThinking