This is a basic introduction to major gemstones commonly found in the cambodian marketplace this beginning level course stresses the important aspects of such gems as ruby sapphire zircon peridot garnet topaz aquamarine crystalline quartz chalcedony obsidian etc in addition to the activities included in the half day class you will have the opportunity to turn theory into practice by testing many more stones during this full day class as well as learn how to use laboratory tools