![]() ![]() The onlyĪrea known to yield gem-quality Ammolite in commercial amounts is located along The Bearpaw Formation is exposed atĮarth's surface in parts of Alberta, Saskatchewan, Montana, and Utah. The ammonite fossils within these concretions sometimes have an outer shell Many of them served as a nucleus for theįormation of siderite concretions which are now found in the Bearpaw Formation. When the ammonites died, their shells fell to the bottom of the ![]() Seaway grew to a diameter of up to one meter - but most were about 1/4 to 1/2 Tightly coiled shell similar to the modern Nautilus. Ammonites (the source organismsįor Ammolite) are an extinct group of marine invertebrates that possessed a Shellfish, sharks, sea turtles, and ammonites. The Western Interior Seaway contained many forms of life, including bony fish, The Bearpaw is composed primarily of marine shale but contains These sediments accumulated and eventually formed a rock unit known as The eastern flank of the young Rocky Mountains washed sediments into the ![]() ItĬonnected what is now the Gulf of Mexico to the Arctic Ocean. The area on the east side of the mountains wasĬovered by a broad body of water known as the Western Interior Seaway. When forces within the Earth were building the Rocky Mountains in what is now The story of Ammolite begins about 70 to 75 million years ago Many stones are impregnated with epoxyįor stability. Some Ammolite is made into doublets, which only requires adding aīacking or transparent cover as needed. Black shale or another material can be used for theīacking. Clear quartz or spinel can be usedįor the transparent cover. Topping it with a transparent cover for protection. These are madeīy backing the fragile iridescent material with a thin slab for stability and ![]() Most Ammolite is used to produce triplets. TheĬolor display can rival fine opal and labradorite in its The colors of an individual stone can run theįull range of the visible spectrum or be limited to just one or two colors. Gem-quality Ammolite produces a spectacular display of iridescent color when it The angle of light striking the gemstone. Shift is how the colors vary with the angle of viewing and The lowest grades having one comparatively dull color predominant. Grades have three or more primary colors or 1–2 bright and even colors, with Violet or gold, which are derived from a combination of the primaryĬolors, that are the rarest and in highest demand. There are also certain hues, like crimson or Red and green are far more common than blue or purpleĭue to the latter's fragility. The aragonite of the shells, preventing it from converting to calcite.Ī large array of color is displayed in ammolite, including all the spectralĬolors found in nature. As the ammonitesĭied, they sank to the bottom and were buried by layers of bentonitic mud that eventually became shale. The ammonites that form ammolite inhabitedĪ prehistoric, inland subtropical sea that bordered the Rocky Mountains-thisĪrea is known today as the Cretaceous or Western Interior Seaway. That thrived in tropical seas until becoming extinct along Exceptional pieces can be cut into gems without stabilization. Usually very thin (often less than one millimeter) and attached to a dark gray The color-producing shell layer of Ammolite is There, twoĬompanies mine Ammolite from thin layers in the Bearpaw Formation where theĪmmonite fossils are found. Mary River in southwestern Alberta, Canada. All of the world's commercial production comes from a smallĪrea along the St. Other less-frequently used trade names for Ammolite are "Calcenite"Īnd "Korite." It is also known simply as "ammonite shell." Ammolite Iridescent aragonite shell material that is found on two species of extinctĪmmonite fossils (Placenticeras meeki and Placenticeras intercalare). Was designated the official gemstone of the City of In 1981, ammolite was given official gemstoneĬonfederation, the same year commercial mining of ammolite began. It is one of few biogenic gemstones others include amber and pearl. With a microstructure inherited from the shell. Which in turn are composed primarily of aragonite, It is made of the fossilized shells of ammonites, Gemstone found primarily along the eastern slopes of the Rocky This blog we’ll be talking about the amazing phenomenon of Ammolite, Ammolite is ![]()
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