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Opals are precious gemstones. The word opal originates from the Greek word “opallos” which means “to see changing of color”.
Sometimes called the “Queen of Gems”, the opal is a symbol of hope, good luck and fidelity. From astrological point of view the opal is considered to be a birthstone of October and represents a zodiacal stone for the sign of Libra.
Opals are composed of non-crystalline silicon gel which over a period of millions of years has hardened and appears in forms of small silica spheres arranged in some kind of regular pattern.
The real beauty about opals is the fact that you will never find two identical ones. Silica spheres in every single opal stone are arranged in a very specific and unique way that could never be replicated. (At least not in a way that mother nature creates its art).
Color and Hardness of Opals
Opal gemstones come in almost every imaginable color from white through yellow, orange, green, blue, red all the way to black which is the most precious of them all.
In many cases a whole rainbow of colors could be displayed on one single, tiny opal gemstone.
Although it took millions of years under extremely harsh and ever changing climatic conditions for opals to form their structure and appearance, they are not very hard gemstones.
Opals contain somewhere in between 6 to 10% of water and on the MOHS scale of hardness, opals rank is about 5.5-6.5
(Friedrich Mohs was a German mineralogist who created a scale of hardness of solid materials based on ability of substances to scratch another substance).
The MOHS scale has a range from 0-10. The higher MOHS scale rating, the harder the substance.
1 - Talc
2 - Gypsum
3 - Calcite
4 - Fluorite
5 - Apatite
6 - Feldspar
7 - Quartz
8 - Topaz
9 - Corundum (Sapphire, Ruby)
10 - Diamond
Opals - Resources and Valuation
The majority of the opals come from Australian opal mines (in fact over 95% of the World’s production). They are not easily found because opals do not usually come in large amounts in one particular spot.
Clusters of opals sometimes might be miles away from each other.
A big amount of opals are found and manufactured throughout Australia and few other places around the World on daily bases. However, only a very tiny proportion of all those opals represents precious and highly valuable opal gemstones. Just the ones with perfect silica sphere composition achieve the high end, mind blowing price and they are always a good, solid long term investment.
Those opals display their breathtaking colors differently every time they are looked at, depending on the light and the viewing angle.
Top quality opals are very rare (in fact more rare than rubies and emeralds) and they often wear a price tag of tens of thousands of dollars.
Opal and opal jewelry drastically vary in their value and price. It all comes up to their quality, their kind and their size. (For more information, please see our “Types of Opals” article).
Basic Facts and Information about Opals
Opals - Name, Meaning and Composition