This is a composite material called Purple Mohave Turquoise. It is low grade turquoise that is color enhanced and compressed into bricks by Colbaugh Processing in Kingman, AZ. We purchase the brick, slice into slabs then make the cabochon. I have it wrapped in 14K gold fill wire. 
Measures 3/4" by 2"
Includes 18" gold plated chain
Gift boxed