To supplement the fossils we dig and prepare ourselves, we have purchased Madagascar ammonites. Who could have ever imagined a small island producing so many ammonites? Some have beautiful nacre, or mother of pearl iridescent shells.
If the shell is damaged, some ammonites are sanded down through their aragonite shell layers and polished smooth to reveal an opalized-looking shell. The beautiful colors gleaming back at you come from light wavelengths intersecting within the aragonite layers. The thicker these layers, the more hues of reds through green refract, and the thinner the layers, the more violet, or blue hues dominate. These ammonites are sometimes referred to as fire ammonites or opalized ammonites.
Sometimes, the whole Madagascar ammonites are sanded further to show the ammonite’s suture pattern. This pattern is where the internal chambers join to the next. The patterns are used as a form of identification and classification by geologists. This suture pattern is often highlighted by the surrounding polished yellow to brown agate and/or calcite. Some of the Madagascar ammonites are cut in half and polished to reveal the inner structure of the ammonite’s shell. The Madagascar ammonite categories for sale on our website are : Whole and Cut & Polished
