mineral
Fire Opal
Hydrated Silica (SiO2·nH2O)
AI-generated identification · may be incorrectHardness: 5.5-6.5 on Mohs scale; Color: Red, orange, or yellow; Luster: Vitreous to resinous; Crystal structure: Amorphous; SG: 1.9-2.3.
- Hardness
- 5
- Color
- Red, orange, or yellow
- Luster
- Vitreous to resinous
Identified More mineral →
Explore Fire Opal in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 5.5-6.5 on Mohs scale; Color: Red, orange, or yellow; Luster: Vitreous to resinous; Crystal structure: Amorphous; SG: 1.9-2.3.
Formation & geological history
Formed by the cooling of silica-rich water in volcanic rock cavities (often rhyolite) during the Tertiary period. This specimen appears to be a cabochon-cut gemstone.
Uses & applications
Primarily used in high-end jewelry as a gemstone and highly valued by mineral collectors for its vivid colors.
Geological facts
Unlike many opals, fire opals (especially from Mexico) can be transparent to translucent and may or may not show play-of-color. Some are called 'Cherry Opals'.
Field identification & locations
Identified by its distinctive orange-red hue and jelly-like transparency. Often found in volcanic regions of Mexico, Ethiopia, and Australia.
More like this
Other mineral specimens
Gneiss or Schist
Gneiss or Mica Schist with Garnet
Metamorphic
Sandstone (with potential mineral staining/concretions)
Arenite (SiO2 based)
sedimentary
Epidote
Epidote | Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)
metamorphic
Pegmatite with Tourmaline and Quartz
Igneous Pegmatite
igneous
Granite
Granite (Phaneritic intrusive igneous rock)
igneous
Septarian Pebble
Septarian nodule / Concretion
sedimentary