Natural Fire opals Overview
 Opal is a poorly crystalline or amorphous hydrous silica that is compact and vitreous and most commonly translucent white to colourless.
Fire opal shows no opalescence. It is usually milky and turbid.
The best qualities are clear and transparent which makes them suitable for being faceted. They are very sensitive to every stress.
Opal usually contains 4 to 9 percent water, but lower and much higher values have been observed. The contents of alumina, ferric oxide, and alkalis are variable but may amount to several percent in light-coloured opals and more if pigmenting minerals are also present. Precious opal has been synthesized. Opaline silica is a friable hydrous silica found near hot springs and geysers.
Physical Properties
| Color |
Fire opal is orange or reddish, and may or may not have an interplay of colours |
| Refractive Index |
1.37-1.52 |
| Chemistry |
Hydrous, Silicon dioxide |
| Hardness |
5.5-6.5 |
| Density |
1.9-2.3 |
| Crystal Group |
Amorphous |
| Ocurrence |
Maxico, Brazil, Guatemala, USA, Australia |
Legend and Lore
Browse Fire opals
The pictures above only represents the general appearance of the Fire opal. Please note that the real Fire opals in our stock will be of varied shapes, color and sizes.
|
