Opal is, finally, one of the noble stones with the biggest increase with respect to its value, especially the black opal. This stone has an increased value guaranteed by its natural rarity, the lack of fields and extraction.

Annual price increase is about 15% to 35 %.

Top crystal and boulder opals of high range have an annual increase about 8% to 25%, due to the shortage of material.

There are not too many investments that have this high profit, so it is a good idea to invest in this fascinating gem.