Investment opal .Black opal from lightning ridge that has red fire is considered by many to be best gemstone investment. This is due to rarity of the opal and extreme rarity to have the desired colours pattern and cabochon. Boulder opal with spectacular colours is now also good investment. Bright red fire with high cabochon and good pattern are highly desired by opal collectors . Gem quality opals are now considered as a percentage of an investors portfolio Gem fire opals have certificate of authenticity and it is the rarity of these gem opals that make a good long term investment as well as the pleasure of having a opal that no one else has in the world. One does not own a gem opal but holds in truest for the next person