We found this stone hard to photograph. It is a far more vivid green than this. People often think that gemstones are precious because they are beautiful. In fact, Dioptase is a brilliant glittering green transparent crystal and I think it's more attractive than emerald. Unfortunately, it's quite soft.
Gemstones have to be hard.
The stones are cut with faces that enhance the glitter, and if the edges get rubbed smooth, then the effect is lost. Also, gemstones need to be held in their metal settings, and a soft stone would soon wear loose, and drop out. This means that you can buy a beautiful stone to admire quite cheaply, as long as you don't want to wear it as jewelry. The precious gemstones, like quartz, emerald, topaz, saphire and ruby are very hard. Diamond, the favourite gem, is the hardest substance known to mankind.