The opal name has various meanings depending on where the name is derived from. Some believe the name is derived from the Indian word for “stone” while others believe the word could be derived from the Sanskrit “upala” meaning precious stone, the Latin word “opalus” meaning seeing jewel or from the Greek word “opallios” meaning to observe color change. Within the opal group there are also three subgroups namely: Opalescent precious opals, common opals and the yellow-red fire opals. Opals are also the birthstone for October.
Precious Opals
These opals are very special with their rainbow-like iridescence which changes as you change the angle of the stone. The cause of these changes is microscopic spheres of the mineral crstobalite layered in interference patterns. The opal always contains water between 3 and 30%. When these are store in moist cotton wool, it aids in increasing the opalescence and it also voids the ageing process. This presence of water makes it sensitive to heat as it can evaporate the water. This stone also features low on the Mohs scale of hardness thus making it sensitive to knocks and pressure.
Fire Opals
The fire opal is as its name describes; the colour of fire such as orange and red. What makes these opals different from the others is that it is usually turbid and milky. Opals with the best quality are also usually transparent which makes them ideally suited to being faceted which makes them look stunning in specific jewelry pieces. This gem is often confused with garnet and rhodochrosite.
Common Opal
As the beautiful birthstone for October, the common opal is opaque with no play of color. The common opal also has a variety of names which are very descriptive and dependent on the color. One example of this is the honey opal; as its name suggests, it is honey-yellow. Each name is very descriptive of what each one looks like so you can get a good idea of their looks in your minds’ eye. Here are some of the names of the common opals: Agate opal, Angel skin opal, wood opal, honey opal, Hyalite or glass opal, Hydropane, Porcelain opal, Moss opal, Prase opal and Wax opal.
Opal Deposits and Colors
Chekoslovakia supplied the best quality opals up until the end of the 19th century. The opals came from andesite lavas in the east of the country. After that, the Australian deposits were discovered and it is known to be the classical country of origin. More famous deposits came from Lightning Ridge and White Cliffs in New South Whales as well as from Coober Pedy and Andamooka in South Australia. The color range of the opal covers a wide spectrum from black, brown, orange, red, green, yellow and blue. So if you are in search of the perfect October birthstone then you are sure to have a fantastic variety of options with this precious and attractive gemstone. Jewelers are able to make magical jewelry pieces by enhancing different qualities in the opal..