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"Made up of the glories of the most precious gems, to describe it is a matter of inexpressible difficulty: there is in it the gentler fire of the Ruby, there is the brilliant purple of the Amethyst, there is the sea-green of the Emerald, all shining together in an incredible union. Some aim at rivalling in lustre the brightest azure...of the painter's palette, others the flame of burning sulphur, or of a fire quickened by oil." ~ Pliny the Elder
Opal History and Lore
Pliny the Elder in his writings tells of a Roman senator called Nonius who, in 35 BC, owned a ring set with a particularly beautiful opal the size of a hazelnut and valued at 2,000,000 sesterces. Roman General Mark Antony decided he must have Nonius' opal, but when Nonius refused to sell, the enraged Antony banished him. Nonius fled Rome, leaving behind all his possesions, save the opal ring which was the cause of his exile.
Opal has been thought to have healing powers in many world cultures, and in the middle ages, it became known as the Opthalmius, or Eye Stone, and was thought to strenghten eyesight. Blonde maidens wore opals to protect their hair from fading or darkening.Bad Luck?
So, how did opal get its reputation for bringing bad luck? There are many theories, but most historians point to the 1829 Sir Walter Scott novel, Anne of Geierstein. According to an article at Opals Down Under, "Having not read the third volume, the public jumped to the conclusion that the heroine has been bewitched, that her magic opal discolours when touched by holy water, and that she dies as a result. On carefully examining the texts, Si Frazier, writing in Lapidary Journal, found all three accusations false. The opal, which actually belonged to Anne's exotic grandmother, turns out to have turned pale as a warning to its owner against poisoning (which was the actual cause of her grandmother's death). Even so, this single work plunged opal prices to half in just one year and crippled the European opal market for decades."
Gemmologist George F. Kunz, author of The Curious Lore of Precious Stones, wrote, "There can be little doubt that much of the modern superstition regarding the supposed unlucky quality of the opal owes its origin to a careless reading of Sir Walter Scott's novel, 'Anne of Geierstein'. The wonderful tale... contains nothing to indicate that Scott really meant to represent opal as unlucky."
What is Opal?
The word opal is from the Latin opalus, probably from a Sanskrit word meaning ‘precious stone’. Chemically, opal is hydrated silica dioxide, SiO2.nH20. It is similar in makeup to quartz, but is softer and has varying amounts of water, between 2 and 20%, with precious opal generally containing 6–10%.
|Types of Natural Opal
Natural opal is opal which has not been treated or enhanced in any way other than by cutting and polishing. There are three types of natural opal.
Opal (Type 1) is what most people think of when they think of gem opal. If it has play of colour, it is referred to as precious opal. Opal that does not have play of colour is called common opal or potch.
Boulder Opal (Type 2) is a seam of opal still attached to the host rock, usually ironstone. Boulder opals with a clean face are the most valuable.
Matrix Opal (Type 3) is distributed throughout the host rock, (usually quartzite, ironstone or basalt) rather than in seams. Most of this comes from Andamooka, Australia, and is often dyed.
The following grading criteria are described in Opal Identification & Value by Paul B. Downing, Ph.D. and are based on the grading system developed by the Lightning Ridge Miners Association in collaboration with several Australian gem industry organizations.
Opals are natural materials and will never be perfectly consistent in colour, brightness, or pattern of fire, or in density of background colour. The higher the degree of consistency, the more valuable the opal.
An opal's cut is important because it not only affects the beauty of opal, but its durability. Most opals are cut en cabochon, or without facets. Many are oval, but they can be cut to nearly any shape, or free-form. An opal should be cut thick enough to not be subject to breakage, but not excessively thick so as to be unattractive. Pay close attention to cut when purchasing loose opals. A stone that is too thick or too thin may be difficult to set properly. The surface should be smooth and all edges should be beveled or rounded to protect the stone from chipping during setting.
Opal inclusions are graded differently than those in other gemstones. Inclusions that don't detract from the beauty of the stone are frequently ignored. Cracks and crazing, however, severely affect value, because they affect both the beauty and durability of the stone.
Most opals are sold on a price per carat basis like other gemstones, but boulder opal is generally priced by the piece since the ironstone matrix is so heavy.
Lightning Ridge Mintabie Nevada Mexico Brazil Ethiopia
-By Cynthia B. Reuschel RGA
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