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Hyalite 0.81cts Fancy Cut 7.90 x 6.60mm Hungary H5.5-6.5 y11451

$115.00 $92.00

1 in stock

Name Range Discount
20% off sale 1 - 10000 20 %

Description

Hyalite

A variety of Opal with formula SiO2•n(H2O) and hardness 5.5-6.5.

 

A colourless variety of Opal. Hyalite is opal-AN, an amorphous silica-glass containing about 3-8% water.

Opal-AN is a term for amorphous opal with a glass-like structure (Graetsch, 1994). The “A” in the name stands for amorphous; the subscript “N” is to imply its structure is network-like similar to silica glass; however, it still contains about 3-8% water, both as molecular water and bound in silanole (SiOH) groups.
Because it has a different structure, it does not show the opalescence (play of color) that is found in precious opal.
Hyalite occurs as globular and botryoidal masses and irregular crusts in volcanic and pegmatite environments where the silica deposits from the gas phase (Flörke et al, 1973). It often shows a strong green fluorescence in UV light. ( from Mindat)

This material is very attractive when seen under short wave,it glows

It comes from Tarcal, Zemplen, Hungary.

Size 7.90 x 6.60mm

wt 0.81cts

Ref y11451