To day there is a problem with synthetic quartz being sold as natural quartz on the gemstone market, so what can you look for to get clues about the origin of the quartz? This diploma thesis is looking at how to identify synthetic quartz and how to distinguish it from natural quartz. To find out, tests were done on natural and synthetic quartz with the help of gemmological instruments, also other ways to identify synthetic quartz with laboratory instruments was looked at. The conclusion was that there is not one test that, on its own, gave enough information to positively identify the origin of the quartz. Several tests where needed to be able to positively identify the quartz as synthetic.