Hardness: 6.00
Refractive Index: 1.37-1.47
Specific Gravity: 2.10
Birthstone: October.
Astral Stone: Libra, Scorpio, Capricorn
Anniversary Stone: 14th
Origination: Australia, Africa, Brazil & the United States.
Care & Cleaning: Opals contain a small percentage of water, which could cause them to dry up and crack prematurely if not cared for properly. In fact, direct exposure to heat could even accelerate this process. Opals should be stored in a separate area, away from other gems or metals that could mar its� surface. If you do not plan to wear your opal for an extended period of time, wrap the stone in a piece of cotton that has been soaked in glycerin. Whether you choose to use olive oil or a plain water rinse to moisten and clean your opals, use either a soft polishing cloth or a piece of silk.
Fiction, Facts & Folklore:
Opal was first found in Southern Australia in 1845.
New opal finds have surfaced on the San Carlos Apache Indian reservation in Arizona.
Opal Butte, Oregon contributes a variety that closely resembles the milky quartz. This little known gem is known simply as the "Oregon Opal".
Tennessee produces a banded opal called the �Candy-Striped Opal�.
The rugged mountains of Utah produce the most unusual �Satin Flash Opal�.
To dream of an opal was a sign of opportunities to come.
The Romans considered the opal a sign of loyalty and hope, while the Arabs believed its fiery colors were caused by lightning which struck the stones as they fell from the heavens.
For years, a rumor circulated in Australia that the opal was a deadly, bad luck stone. Eventually, this story was traced back to Australian diamond dealers who perpetuated the thought in order to protect their diamond market from the surging demand for opals.
For additional information, see �black opal� and �fire opal�.