Opal is the gorgeous birthstone of October. Opal can be found in Australia, Ethiopia, Brazil and some parts of the United States. Precious opal ranges from clear through white, gray, red, orange, yellow, green, blue, magenta, rose, pink, slate, olive, brown, and black. Of these hues, the reds against black are the most rare, whereas white and greens are the most common.
Opal was formed many millions of years ago, when a combination of silica and water flowed into cracks and spaces in the ground. This then gradually hardened and solidified to become opal.
The opal is said to be many things including the most powerful of healing stones, the stone of hope, the stone of great achievement.