Opal has long been considered one of the most beautiful gemstones in the world because it displays all the colors of the visible spectrum and each piece of jewelry becomes unique.
Opal, one of the most spectacular semi-precious stones in the world, is the stone of the October natives. The mysterious crystal has a brilliance of color that surpasses that of diamonds. This semiprecious stone has the power to heighten emotions and remove inhibitions, bringing stability, prosperity, success, luck, love and peace.
Formed by rain – there are many theories on the formation of this semi-precious stone, but it is believed that opal is formed when water seeps into silica-rich crevasses and rocks. Opal is the product of seasonal rains that soak the dry land in regions such as Australia’s semi-desert ‘outback’. After the water evaporates, a mixture of water and silica is left behind, which crystallizes over time into the stone we call opal.
Origins and legends
Opal is believed to have originated in India (the source of the first opal stones brought to the Western world), where in Sanskrit it was called upala, a ‘precious stone’.
In Greek “opalios” means “colour changer”. Many cultures and civilisations have attributed supernatural origins and powers to opal. The ancient Greeks believed opal to be the gift of prophecy and to ward off disease. In ancient Rome, this jewel symbolised love and hope. The Romans gave it a name – opalus – which was synonymous with ‘precious stone’.
In the Middle Ages it was considered a stone that brought good luck, as it was believed to possess all the virtues of the gemstones whose hues were present in the colour spectrum of that opal. It was also believed that if wrapped in a fresh bay leaf and held in the hand it conferred invisibility on the person holding it. The Bedouins believed that the opal fell from the sky during storms. According to Arabic legend, opal stones are what remain when lightning strikes the earth.
Europeans saw opal as a symbol of purity, hope and truth. That’s why opal was considered the luckiest and most magical of all gemstones because it could show all colours.
Characteristics of opal
Opal is a mineraloid based on a combination of silicon and water. It is a silica gel, with percentages of water ranging from 3 to 10%, some specimens can contain as much as 20% water. In nature, it forms at low temperatures in the cracks of various types of rock, often near hot springs.
Cleavage (property of splitting into slabs): For opal, cleavage is non-existent because when a mechanical force is applied to it, it does not split in any direction, resulting in the phenomenon of breakage.
Hardness: 5 – 5.5 on the Mohs scale
Density: 2.0 – 2.25
Crystallisation system: amorphous
How Opal is formed
Opal is known for its unique way of intermittently displaying rainbow colors in a play of shades. There are two main classes of opal: precious opal and common opal. Unlike common opal, precious opal has a play of color, being made up of microscopic spheres. As light waves travel between the spheres, they diffract or bend, then split into rainbow colors, also called spectral colors. Opal has a variety of colors, some of which are very common, such as white and green, but also very rare, such as black.
Although experts divide opal into several different categories, five of the most important are:
White or light opal: translucent to semi-translucent, with color play on a white or light gray background color, called bodycolor
Black opal: translucent to opaque, with colour play on a black or other dark background
Fire opal: transparent to translucent, brown, yellow, orange or red. This opal – which often has no colour play – is also known as “Mexican opal”.
Boulder opal: translucent to opaque, with color play on a light to dark background. Fragments of the surrounding rock, called matrix, become part of the stone
Water opal: from transparent to semi-transparent, with a light background. This type shows an exceptional play of colour.
Where opal is found
Opals are very rare and therefore not mined industrially. Opal has been found on all continents, but 97% of opals come from Coober Pedy, southern Australia. Australia’s fields are the most productive in the world for this stone. Lightning Ridge, a small town in New South Wales, Australia, is famous for producing black opal, the stone’s rarest color.
Australia is also a source for most types of opal. White opal is found in the White Cliffs area of New South Wales, as well as in Mintabie, Andamooka and Coober Pedy in South Australia. Boulder opal, which comes from a single location in the world, is mined in Queensland.
In Ethiopia, opal is found near the village of Wegel Tena in Wollo province. The stones here range in colour from white, yellow, orange and reddish-brown to ‘chocolate’ brown. Another mine, in Ethiopia’s Shewa province, extracts the most coveted black opal, as well as orange or white opal. Querétero, a state in Mexico, is known for mining fire opal in yellow, orange and reddish orange to red colours.
The mines are a tourist destination, and getting to them becomes a real challenge with the difficulty of the routes.
Others have been found in Central Europe, Honduras, Indonesia, Madagascar, Peru, Turkey and the United States.
Energetic and spiritual properties
Opal stone is believed to have healing properties on all eye diseases, as well as stabilizing the health of skin, hair and nails, and balancing water retention in the body. On a spiritual level, it attracts angelic entities and enhances spiritual communication with the Divine.
Opal is the lucky charm of the Libra sign and influences those born under the influence of the numbers 8 and 9. The effects on the wearer of opal jewellery are very beneficial, acting as a protector, bringing good luck and helping the wearer to reach their full potential.
Opal is also the stone intended to celebrate the 14th wedding anniversary, and depending on the colour, opal, can have different characteristics and energetic indications, as follows:
Black Opal – enhances sexual activity, activating the first two chakras, amplifies lived spiritual experiences, brings good luck and has the ability to transform fears and inhibitions that hold us back, giving us optimism and courage in return;
White Opal – balances energy fields and increases the body’s well-being; alleviates stress;
Fire Opal – offers protection against dangers, increases personal strength, supports the body during emotional turmoil, and is a stone indicated for release and letting go of the past. Fire Opal balances the secretion of the adrenal glands;
Blue Opal – is considered an ultimate stone for the fulfillment of all forms of desires. This stone helps to see beyond the physical world, to perceive the wonders in nature that underlie life;
Green Opal – is purifying and rejuvenating, promotes emotional restoration and strengthens relationships. It has the ability to filter information and change the way we think, as well as the outlook on everyday life.
How to care for opal
Opal has a low hardness, about the same as glass, so it needs to be treated with care to avoid damage. An opal is purified in warm water and PH-neutral liquid soap. A brush can be used to clean the narrow spaces between the stone and the jewellery. It is recommended not to wear opal jewellery if there is a possibility of it being scratched or broken. Opal can crack if kept in a dry environment, if mixed with other harder stones or if it undergoes large temperature changes.
We recommend that opal jewelry should not be placed in water. Opal absorbs water when wet or exposed to high humidity. When the stone is wet, its color will change and it will lose its lustre until it dries completely. Prolonged exposure to sun and heat should also be avoided, as opal loses water from its composition, becomes brittle and the play of colors disappears. Contact with cosmetics, chemicals and detergents is contraindicated.