This is the best possible color for blue Zircon. It is cut in oval with no window and sold at a discounted price because of this small crack on one side. This crack is hardly visible to the naked eye but this Zircon is still sold at a discounted price. As you can see in some photos it is well on the side and a skilled jeweller should easily be able to hide it on the gemstone. This grade a blue zircon is calibrated at 8x6 mm.