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Dimensions
2.9"/45mm approximately
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Cleoniceras Red Iridescent Ammonite Fossil - SP7658 | ||
| £30.00 | |||
Description
Superb Madagascan Cleoniceras Ammonite specimen, also known as Red or Iridescent Ammonite, has been highly polished to reveal the naturally occurring and desirable iridescent lustre. Very similar to the Ammolite fossils from Alberta, Canada, described as Ammolite this play of colours is caused by the play of light against aragonite which replaced the original chitin shell, when fossilisation took place. This Ammolite shell is often used in jewellery manufacturing and is much sort after by collectors of fossils as well as semi precious gem collectors. Ammonites of this type are becoming much more difficult to acquire.
The image is of one Specimen at different angles
Ammolite
recognised by the Coloured Stones Commission in 1981 as a gemstone, ammolite primarily comprised of Aragonite which is also the substance of natural pearls. Unlike most other gem, where the array of colours come from light refraction, the iridescent colour of ammolite comes from interference with the light that rebounds from the stacked layers of the aragonite. The ordered thicker stacks cause red gem colour, the less ordered thinner stacks for the green gem colour and very thin unordered stacks for the blue colours.Brief Ammonite History
Ammonites, part of the Ammonitida [order], Ammonoidea [sub class], Cephalopoda [class], of marine invertebrates were fascinating and believed to be aggressive creatures, with their extremely large eyes they could easily hunt at night or at great depth where little or no light penetrates the deep oceans much as the persisting modern day Nautilus Pompilius [Emperor Nautilus], which swims the Pacific.at a depth of between 200-400m Off the Great Barrier reef sightings of Nautilus have been made. Showing the pressures these Cephalopods can attain. Suture Patterning, suture patterning the complex ,in some cases, almost frilly patterning on the surface of polished fossil ammonoid specimens, is in fact the markings from underside of the shell interlocking system of the cephalopod, which gives the living Cephalopod greater strength enabling it to resist the great pressures at great depth. Ammonites extinction around 74 mya [ammonite range 330 m.yrs], pre grt mass extinction 65 mya, at the end of the Cretaceous Period which ended the rule of the dinosaurs. Very important as an Index Fossil, often possible to link the sediment layer in which found to specific geological time periods. Largest ammonite found was around 2.5m diameter, found in Germany. Ammonite, Named by the Greek ancients [Ammon], after the Egyptian God deity Amun, with ram horn ears, similar to the concentrically formed shell. Closet living relatives [subclass Coleoidea], octopus, squid, and cuttlefish.