It's fascinating to have an idea of which gemstone sits with which gemstone family.  Various organisations in the world of gemstones use different terminology for different connections, but for a simplistic overview the table below would generally be considered as the main family names and their members.  However, it’s not straightforward on what relates certain gemstones to others ~ some are related due to their chemical composition being the same, whereas others share the same crystal structure, but vary in chemical composition.