The crystal structure of zircon is tetragonal crystal system. The natural color of zircon varies between colorless, yellow-golden, red, brown, blue, and green.
High zircons gemstone are fully crystalline and give the higher RI, DR and SGs of the zircon family.
Low zircon gemstone, over geological time low zircons have lost their crystalline structure due to the continuous bombardment of the crystal structure by alpha particles emanating from included uranium and thorium
Zircon gemstone like spinel and corundum truns up in a number of fancy colours., red, rad-orange, brown, blue, yellow, green and colourless zircon