IRIDESCENT GEM AMMONITE
Placenticeras meeki
Late Cretaceous
Bearpaw Formation, southern Alberta, Canada
It is only in this small North American formation, straddling the border of Montana and Canada on the eastern slopes of the Rocky Mountains, that this incredible biogenic gemstone is found. Millions of years of bentonite action preserves the nacreous lining of the ammonite’s shell, and converts the snow-white aragonite into these fiery, iridescent shades. This excellent specimen boasts complete ammolite coverage, flashing with an incredibly vibrant electric green and shining gold, hints of red and orange at the edge, and best of all, generous areas of the rare purple coloring only occasionally seen on these specimens. With good three-dimensionality and fine detail to the center whorl, it is highly attractive for both the cabinet and for dramatic display. It measures 10 3/4 inches wide.