Opal is definitely the only stone, which possesses natural beauty, being inside the matrix, while other gems are required to be cut and polished, until they acquired their brilliant effect.
However, we have to admit, that speaking about the Opal, as gemstone, the only variety, called “Precious Opal” (or “Noble Opal”) is used for jewelry purposes and it possesses real commercial value, although there are numerous of varieties of that gem.
Properties of Opal, that could be useful to buyers
Primarily, the Opal is remarkable due to its color, more precisely, to its possibility to reflect the light, due to its peculiar structure. This structure of the Opal has intrigued yet Isaac Newton, who has supposed that the possibility of the Opal to reflect light such a strange way, due to the existence of many defects or, more precisely, the rifts inside it.
Unfortunately, the Opal is able to lose that advantage, due to unstated cause, but fortunately, it could acquire it again. Many researches and investigations have been established, concerning of that peculiar feature, no one of the researchers has found of reliable explanation for this fact.
Secondly, the Opal is very soft gemstone (being of 5.5 to 6.5/10, according to the Mohs Scale of Hardness), it is even softer than the Peridot, therefore, the consumer should wear it very neatly.
Origin and History of Opal
Before this gemstone was discovered in Australia, where the miners called it “potch,” (that meant “colors”), it was supplied from Hungary.
Despite their Hungarian origin, these gemstones were called “Oriental Opals,” due to the fact that these gems were delivered by the Greek and Turkish merchants in Holland from the spot, called Czernowitza, located, however, in Hungary. Exactly those Opals are still the most valuable on the market.
The first Hungarian mines were discovered in XV century, but have been almost exhausted soon. Subsequently, the mines were developed in Australia, Honduras and Mexico.
Australian opals are chiefly delivered from White Cliffs, New South Wales. However, there are other locations such as Barcoo River and Bulla Creek in Queensland.
Mexican mines, located in the State of Queretaro, contain primarily of fire opals.
Varieties of Opal
There are such varieties of the Opal as:
- Common Opal – yellowish or greenish semi-precious stone possesses opaque and translucent properties. It is used for cheap jewelry and ornamental purposes;
- Fire Opal – is widespread Mexican Opal, represented fire-like effect in the sunshine. It is usually of yellowish or reddish tint;
- Wood Opal is usually represented the concentric rings of the tree, from whence its name;
- Resin Opal – is usually possesses yellow color and resinous in appearance;
- Agate Opal – possesses so-like Agate-structure, which represents different shades of color;
- Liver Opal or Menilite – is liver-coloured variety of common Opal;
- Hyalie – also known as “Muller’s glass,” possesses transparency, similar to a glass, whereupon it’s a colorless variety of common Opal;
- Hydrophane – that variety of Opal, being in water becomes translucent, is usual of opaque yellow or white color.
Unusual properties, attributed to Opal
In all senses, the Opal was an unusual gemstone for our ancestors, therefore they have endowed this gem with various mystical and even magical properties. Some of these superstitions came in our modern life, thus, according to the modern charts, Opal is the alternative birthstone for October.
The authors of XVI century have endowed Opal by the unusual possibilities, that allowed it to make its wearer a general favorite, to protect him against suicide and to enhance the keenness of his sight. According to medieval treatises, the Opal has been used to cure the diseases of internal organs, including the stimulation of the heart, mood enhancement and resist infection.