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.
Just three of the very oldest zircons have been found, ones that date back to almost 4.4 billion years ago. Their extreme age always makes the dates suspect, because of possible radiation damage.