Recognize the session layer of the OSI model ; List the seven layers of the OSI model ; Discuss the responsibilities, functions and protocols of the session layer ; Specify the six session layer protocols
Currently, the most popular color for this gem is the blue zircon. Most blue zircon, which is considered an alternate birthstone for December, is normally a pastel to medium blue in color, but some exceptional gems have a bright blue color. Beyond blue, Zircon is also available in green, deep red, yellow, brown, and orange.
Fine clean specimens in pure green sell for prices around $250 to $300 carat, while olive-green zircons are typically less. Natural zircon is in limited supply and can usually be found only from specialized gem deaers. You are unlikely to find it in retail jewelry stores.