This is an absolutely stunning, 14.6" wide ammonite (Placenticeras costatum) fossil preserv

This is an absolutely stunning, 14.6" wide ammonite (Placenticeras costatum) fossil preserved entirely in precious ammolite. It is in excellent condition with a tremendous amount of flash, very vivid colors and well pronounced ribbing. It comes from the lower layers of the Bearpaw shale at the Korite mine in Southwest Alberta. This layer produces the highest quality, ammolite gemstones.

From: https://www.fossilera.com/fossils-for-sale/ammolite