Ammolite may be a rare, gem-quality, iridescent material. It's cut from the fossilised shells of extinct ammonites (ancient sea creatures) found only within the Bearpaw Formation in Alberta, Canada. With a good vary of dazzling colours and patterns, this organic gem is very desired for freeform natural cabochons and assembled jewelry items.
Ammolite Information
DATA | VALUE |
Name | Ammolite |
Alternate Common Names | Korite or calcentine |
Crystallography | Amorphous, Orthorhombic (aragonite) |
Refractive Index | 1.520-1.670 |
Colors | Ammolite can be found in any color known in nature or the imagination. It can also have a vast array of color combinations in every square centimeter. See "Comments" below. |
Luster | Vitreous to resinous. |
Hardness | 3.5 – 5.5 |
Specific Gravity | 2.60-2.85 (Pure aragonite: 2.95) |
Birefringence | 0.15 |
Cleavage | None, parting present |
Heat Sensitivity | Yes |
Wearability | Good to poor |
Enhancements | Opticon and lacquer stabilization |
Transparency | Opaque, thin sheets used in assembled stones may be translucent to transparent. |
Phenomena | Iridescence. |
Formula | CaCO3. Variable, may include aragonite, calcite, silica, pyrite, or other minerals |
Optics | a = 1.520; γ= 1.670. |
Etymology | From ammonite, the fossils of an extinct cephalopod with a spiral shell like a ram's horn. Ammonite was named after the Ancient Egyptian god Amun, who was represented with ram's horns. |
Occurrence | Sedimentary |