large iridescent straight Ammonite (rare)

Item Description

Huge, RARE, extinct straight-shelled fossil Ammonite Cephalopod from Alberta, Canada. The genus is Baculites and is Upper Cretaceous in age (100.5 to 66 MYA). The fossil is probably from the Bearpaw Shale. This impressive, well-prepared and preserved fossil also has fantastic, iridescent, opal-like hues of neon-red, orange and green. it is, as you must expect, repaired by the collector who found it. The opal-like material is called Ammolite. It is an organic gemstone found in North America made of the fossilized shells of ammonites and are composed primarily of Aragonite. The iridescence is due to the microstructure of the Aragonite that comes from interference with the light that rebounds from the stacked layers of the thin platelets that make up the Aragonite (Wikipedia). Iridescent straight ammonites of this striking size and rich iridescent color saturation are RARE, compared to iridescent coiled Ammolite Ammonites from Alberta. 768 grams or 1.7 pounds mass. RARE on the market in this size and dramatic quality. It is hard to value such things - and we are not a fossil dealer, so we pass on some deals like this, if they came in a mineral collection purchase!