This is a HUGE slab of Lapis Lazuli, just over 7.5"!
 
This Lapis has a very deep blue hue, with patterns of pyrite running throughout the entire stone.  The depth of the blue color is consistent across the entirety of the piece.
 
Lapis Lazuli is one of the most sought after stones in use since man's history began. Its deep, celestial blue remains the symbol of royalty and honor, gods and power, spirit and vision. It is a universal symbol of wisdom and truth.