gemstone
Fire Agate
Chalcedony (SiO2)
Hardness: 6.5 to 7 on the Mohs scale; Color: Brown, orange, red, green, with iridescent play of colors; Luster: Waxy to vitreous; Crystal structure: Trigonal (microcrystalline quartz); Specific gravity: 2.58 to 2.64
- Hardness
- 6
- Color
- Brown, orange, red, green, with iridescent play of colors
- Luster
- Waxy to vitreous
Identified More gemstone →
Explore Fire Agate in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6.5 to 7 on the Mohs scale; Color: Brown, orange, red, green, with iridescent play of colors; Luster: Waxy to vitreous; Crystal structure: Trigonal (microcrystalline quartz); Specific gravity: 2.58 to 2.64
Formation & geological history
Formed in areas of tertiary volcanism where hot, silica-rich water filled cavities and fissures in surrounding rock over millions of years.
Uses & applications
Used primarily in lapidary arts, high-end artisan jewelry, and as a collector's specimen.
Geological facts
Fire agate gets its iridescent rainbow colors from interference phenomena caused by thin layers of limonite or other iron oxides deposited between the microscopic chalcedony layers.
Field identification & locations
Easily identified by its botryoidal, grape-like exterior and the fiery, iridescent flash visible beneath the surface when polished or windowed. Found notably in the southwestern United States and northern Mexico.
More like this
Other gemstone specimens
Diamond and Gold Jewelry
Carbon (Diamond) / Au (Gold)
gemstone
Ammolite
Ammolite (Biogenic Aragonite with trace elements; fossils of Placenticeras meeki and Placenticeras intercalare)
mineral
Cubic Zirconia (simulant) or Diamond
ZrO2 (Cubic Zirconia) or C (Diamond)
gemstone
Black Opal Ring (Carved Opal)
Hydrated Silicon Dioxide (SiO2·nH2O)
gemstone
Red Jasper
Silicon Dioxide (SiO2) with Hematite inclusions
sedimentary
Cubic Zirconia (or possibly Diamond)
Zirconium dioxide (or Carbon)
gemstone