For your consideration is a 19.3ct piece of Ready-to-Dop  London Blue Topaz preform pair.
 
NOTES:
These stone are well shaped with a good symmetry. These would be ideal for cutting a pair of cube gemstone earrings. A skilled cutter should be able to yield a pair of finished cubed gemstones that are 6-8ct each.
 
*Please refer to the photos/video for color and clarity details.
 
Mineral: London Blue Topaz
Origin: Brazil
Weight: 19.3 ct
Dimensions: 8mm x 8.5mm x 9mm 
Clarity: Clean
Treatment: Irradiated