Chemical Formula: SiO2

Chemical Name: Silicon Dioxide

Mineral Class: Tectosilicate

Mineral Notes: Hyalite is a glassy form of Opal. It is usually founds as colourless, globular concretions. It is also called Muller's Glass. Although classified as an opal it is never opalescent, although it is often faintly iridescent under certain lighting conditions.

Description: This is one of the best specimens of Hyalite we have seen. It consists of a brown matrix upon which sits a froth-like mass of fused Hyalite globules. The mineral is so clear that it is almost glass-like and has a remarkably bright luster. An unusual specimen for any collection.

Location: Valei, Bohemia, Czech Republic.