Opal is the birthstone for October and traditionally it is also the gift given for a 14th wedding anniversary. Opal is Australia’s national gemstone.
The name Opal derives from the Greek Opallos, meaning "to see a change (of colour)". Opals form as colourless, white, yellow, red, orange, green, brown, black or blue, and may be transparent, translucent or opaque. They have a brittle tenacity and are usually cut en cabochon to show their full play of colour. An Opal's beauty is the product of contrast between its colour play and its background. The colour is not due to any pigment in the stone, but are optical effect created when the microscopic spheres of silica hardened in an orderly grid-like pattern.
Australia not only mines 95% of the world’s precious black and white opal but offers opals of many varieties used in jewellery, including milky opal, jelly opal, boulder opal, crystal opal and some fire opal.
Of the three basic types of Opals, “Precious Opal” also called “Rainbow Opal” is the rarest, mined in a limited number of locations worldwide and produces brilliant flashes or streaks of iridescent colour when turned in the light, a phenomenon known as “play of colour.”
“Common Opal” or “Potch” is found in many places throughout the world and does not exhibit a play of colour. It usually has a milky or pearly lustre, known as “opalescence.”
The third type, “Fire Opal” is a transparent to translucent Opal with a body colour of vivid red, orange or yellow, most commonly mined in Mexico. It typically shows no play of colour, though occasionally a stone will have a weak display or exhibit bright green flashes.
Long known as the Wish Stone, the October birthstone is supposed to promote love and romance and to grant wishes and personal happiness. Opal is a stone of inspiration which enhances imagination and creativity. Opal is said to enhance memory and is also used to decrease confusion.
Just as Opal absorbs and reflects light, it picks up thoughts and feelings, desires and buried emotions, amplifying them and returning them to the source. Opals promote a sense of calm security, easing stress and depression, and encouraging one to stop worrying to better direct one’s thoughts and energies.
Opals centre the mind and are stones of happy dreams, particularly soothing for children and those who have always slept badly or had recurring nightmares with no apparent reason.
A stone of protection, Opal is a marvellous shield to keep from absorbing other people’s negative thoughts and energies.