Ammolite is the mineralized, fossilized and opalized remains of an ammonite shell which was exposed to tectonic pressure, mineralization, and intense heat.
Ammolite (also known as korite, calcentine, or Buffalo Stone.) is a fossilized, opalized ammonite shell used as a gemstone (it is the shell of the ammonite, a fossilized marine animal, a cephalopod). It is a gray, iridescent stone with flashes of green, red, yellow, blue or purple (blues and purples are rare); the color changes as the stone is turned. Ammolite has a hardness of about 4 (it is very brittle before it is treated) and a specific gravity of 2.8. Ammolite is usually treated with a colorless, hard material to increase the strength of the stone and is often mounted as a doublet or a triplet (with a quartz top layer and a shale underside). Ammolite is only found in southern Alberta, Canada.