"Gem" Ammonite. Placenticeras costatum. Late Cretaceous, Bearpaw Formation. Alberta, Canada. ... (Total: 2 Items)

Description

"Gem" Ammonite
Placenticeras costatum
Late Cretaceous, Bearpaw Formation
Alberta, Canada

Ammonites are recognized as mollusks with shells, and these marine invertebrates belong to the cephalopod class. Only living in the outermost chamber, Ammonites continuously "built" new shell as they grew. They were actually predatory and had sharp, beak-like jaws inside a ring of tentacles, allowing them to function as carnivores. As Ammonites moved through the ancient seas, they were propelled by squirting streams of water and using a tubelike structure called a "siphuncle" which siphoned air and regulated buoyancy. All Ammonites went extinct at the end of the Cretaceous Period, at the same time as all of the Dinosaurs, some 65 million years ago.

This exceptional "gemmy" Ammonite features fabulous colors on both sides with green, red, and gold being the dominant shades. This specimen is rather well inflated which is to be noted since the majority of freestone Ammonites are typically quite compressed. Measuring a robust 10 inches (25.4 cm), this is a sizable example. The shell nacre has been preserved as Ammolite, a bona fide gemstone material certified as such, since 1981, by the World Jewellery Confederation. This extremely bright and colorful Ammonite is a rare example of the costatum species and was mined at the Korite Oxbow Mine which has been closed since the early 2000s. The iridescent shell has sections exhibiting the "dragon skin" pattern in the Ammolite, adding to the character of this particular specimen. These "gemmy" Ammonites are virtually only found in Alberta, Canada.

This particular specimen is collector grade, without question, and is truly both a fossil and a gemstone. This Ammonite exhibits some indentation and several patches without the colorful shell material, but, overall, the specimen is in good condition and a superb representation of this type of Ammonite. There are even hints of blues and purples on the shell evidencing that it never looks the same twice. The specimen comes with a custom "V" wood stand and a laminated Certificate of Authenticity.
Overall Measurements: 10.0 x 9.0 x 2.0 inches (25.4 x 22.9 x 5.1 cm)

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