ABSTRACT
The durability of a gemstone In Chapter 1, mention was made of the essential qualities of a gem material. These qualities included beauty, rarity and hardness. While the beauty and rarity of a gemstone may be the prime factors in its selection for use in jewellery, its durability or hardness must also be taken into consideration. The reason for this is that the gem must be capable of withstanding the wear and tear to which jewellery is subjected in everyday use. While a ring-mounted gemstone may have to endure the occasional hard knock, it is the presence in airborne dust of microscopic particles of silica or quartz that is the real test of a gem’s durability. These particles are in continual contact with the gem, and if the stone is relatively soft they will gradually abrade its polished surface. For this reason, the hardness of a material is defined in gemmology and mineralogy as the ability of that material to resist abrasion.
