Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. ZIrcon (including hyacinth or yellow zircon) is a mineral belonging to the group of nesosilicates. ITs chemical name is zirconium silicate and its corresponding chemical formula is ZrSiO4. A Common empirical formula showing some of the range of substitution in zircon is (Zr1-y,REEy)(SiO4)1-x(OH)4x-y. ZIrcon forms in silicate melts with concentrated incompatible elements and accepts high field strength elements into its structure. FOr example, hafnium is almost always present in quantities ranging from 1 to 4%. THe crystal structure of zircon is tetragonal crystal system. THe natural color of zircon varies between colorless, yellow-golden, red, brown, blue, and green. COlorless specimens that show gem quality are a popular substitute for diamond; these specimens are also known as "Matura diamond".