Marked on back. Five sided shaped ammolite with 18K yellow gold surround. Swirl at the top. 

Size: 2 1/2 x 3 1/2 in. 

Gross Weight: 41.4 dwt. 64.4 g. 

#7061 #21 . 

Ammolite is an opal-like organic gemstone found only in the eastern slopes of the Rocky Mountains of North America from Saskatchewan to Montana. It is made of the fossilized shells of ammonites from the Upper Cretaceous period 100 million years ago with a microstructure inherited from the shell, and is one of the only biogenic gemstones besides amber and pearl. Ammolite is also known as aapoak (Kainah for “small, crawling stone”), directly referencing the iridescent play of colors across it, mostly in shades of green and red. The iridescence is due to aragonite that makes up the microstructure: unlike most other gems, whose colors come from light absorption, interference with the light that rebounds from stacked layers of thin platelets causes the visible shift. Exposed to the elements and compressed by sediments the thin ammolite tends to crack and flake in a tessellated appearance, sometimes described as a “dragon skin” or a “stained glass window” pattern. Less than 50% of the ammolite excavated is of suitable quality for jewelry, and compared to most other gems it has a very scant history, not garnering interest in Western society until the 1970s after entering the market. The Blackfeet tribe know ammolite as iniskim, meaning “buffalo stone,” and have long believed it to possess amuletic powers. In the late 1990s, practitioners of feng shui began to promote ammolite as an “influential” stone with what they believe is the power to enhance well-being and detoxify the body by improving its flow of energy or “chi.” Due to its delicacy and susceptibilities to the elements, nothing harsher than mild soap and warm water should be used to clean ammolite jewelry; ultrasonic cleaning should be avoided. Japan is the largest market for ammolite, followed by Canada and then the Zuni Native America craftspeople.