When it comes to describing an Australian gem, there are plenty of synonyms that can be used to capture its beauty, rarity and worth. One of the most common synonyms that's often used is "precious stone", which aptly describes the value of these gems. Other synonyms that could be used to describe an Australian gem include "jewel", "treasure", "gemstone" and "crystal". These words help to emphasise the stunning natural beauty of Australian gems, highlighting their unique colours and patterns. Other suitable synonyms include "ornament", "beauty", "adornment" and "decoration", each of which describes the visual appeal of these stunning natural treasures.