The opal, rarer than the diamond

Thanks to a subtle alchemy between water and mineral, the opal is both a source and a symbol of light . Its pearly luster and iridescent reflections explain its exceptional reputation.

What is the meaning of opal?

This luminous stone finds the origin of its name in the Sanskrit term – classical Indo-European language – upala which means "precious stone" .

In Australia, the opal was even nicknamed the “rainbow serpent”. During the Middle Ages, the opal was famous under the name of "ophthalmios" which literally meant "stone of the eye".

The opal symbol of light

Among all the stones, the opal is the one that symbolizes light. Its mineralogical properties give it luminosity, a pearly shine and iridescent reflections that produce a striking aesthetic effect. Layering in opals is responsible for a phenomenon called iridescence . This is the source of a remarkable visual impression according to which an object changes color depending on the angle of view. The name of this stone is even at the origin of a specific property: opalescence . This is said to be a translucent material with a milky tint and iridescent reflections.

What are the different types of opal?

Opal can be opaque to transparent and in various colors. Many varieties exist.

The common opal , the majority in this category of minerals, is a variety with milky hues sometimes pigmented with pale colors such as grey, yellow or pink. There are also sub-varieties, such as Andean opal or purple opal.

The hydrophane opal , white and opaque, has a unique feature. It becomes transparent when immersed in water.

fire opal is a variety whose color spectrum extends from orange-yellow to incandescent red.

THE noble opals are white or black and feature brightly colored iridescence.

The different names that characterize each opal stone are directly linked to their place of extraction.

What are the most beautiful opals?

There are five mainly, the most expensive, the rarest...

Opals with deeper contrasts are often considered more valuable than those with lighter colors. This is mainly because a darker mineral returns the colors of opalescence better, making it look brighter than a lighter stone.

Boulder opal

It is probably Australia's most popular opal. It is also one of the most sought after opals by collectors and the rarest, as it is only found in Australia and accounts for only 5% of opals mined. Boulder opal was discovered in desolate, dry and hostile lands in central Queensland. Geologists and prospectors estimate that no more will be found by 2030.

To realize its rarity, in the 80s there were around 200 opal miners in Queensland. In 2022, they are only about twenty. Few occurrences of discovery associated with the few opal prospectors, leads to understand that the Boulder will become even more expensive than today.

black opal

It is reputed to be the most expensive type of opal in the world. It is also the most valuable and popular of all opals. Originally from New South Wales, this stone is 130 times rarer than diamonds.

This stone therefore differs in its black matrix color which comes from the dissolution of sandstone silica with water. This opaque, silica-rich liquid from the sandstone then rushes into natural faults and cracks or voids created by the decay of fossils. When the water evaporates, a silica deposit forms. The sandstone minerals contained in the solidified siliceous water thus give a black color by the iron oxide that the opal contains.

Welo opal, opal from Ethiopia

It was first discovered in 2008 in Wegel Tena, a small town in the Tsehay Mewcha district of Ethiopia's Welo province.

Ethiopian opal is sometimes irregularly shaped, appearing in veins and masses with sharp edges, and the host rock often extends deep into the opal mass. This results in a limited yield when cutting, since a classic cabochon shape requires deep grinding of the stone.

fire opal

Opals from Mexico or Brazil are famous for their “fire”, their amazing orange, yellow and red colors. The most sought-after specimens exhibit a brilliant, fiery red or orange hue as well as a uniform color.

Stone collectors value “fire opals” for their gorgeous colors and generally lower price, ideal for starting a collection. However, fire opals are very sensitive to heat and therefore to the drying out of the stone, making it extremely fragile, especially to wear it as jewelry.

white opal

White opal is the most common opal in Australia. It is mined in southern Australia and due to its lighter coloring is easily distinguished from other forms of opal. The white tone is caused by the magnesium oxide in the silica and is usually described by a pale or milky white tint. This form of opal is more common, but not cheaper.

The most valuable aurora australis opal

The aurora australis is the most valuable among the black opals, weighs 180 carats and was estimated at one million Australian dollars. This opal was named as such for its resemblance to a night sky filled with bright lights. It is a stone found in 1983 in a mine in Lightning Ridge, Australia, and it is considered the most valuable black opal in the world.

The opal therefore brings together a rich variety of gems with multiple hues.

What are the mineral properties of opal?

Opal, or solid silica hydrogel, is composed of water and silica . Under the effect of heat, it is transformed into quartz. It is found in sedimentary rocks or igneous rocks.

• Band : quartz
• Crystal system: amorphous, clustered aggregates
• Composition : hydrous silicon dioxide
• Colors: various colors
• Density : 1.9 to 2.5
• Hardness : 5.5 to 6.5
• Transparency: transparent to translucent
• Glow : glassy
• Shapes: Kidney masses, pseudomorphs and fossil material
• Deposits: Australia, North America, Central and South America, Japan

What are the properties of opal in lithotherapy?

The main symbol of opal is light

Thanks to mineralogical phenomena such as iridescence and opalescence, this stone offers us a delicate and hypnotic spectacle mixed with iridescent reflections and pearly effects. With this powerful characteristic, the opal carries with it multiple virtues resulting from its vibration and its luminosity, such as clairvoyance, clarity, concentration, intuition and joy.

And the second element that symbolizes this mineral is water. 

An important part of its composition, water contributes to its unique radiance. In terms of physical health and psychic balance, the water element, omnipresent in the structure of the opal as in the human body, has beneficial and stabilizing contributions.

The chakra mainly associated with this stone is the forehead chakra . It is naturally in connection with the notions of intellectual clairvoyance and clarity of mind that its resonance with opal fits.

Opals have many virtues that are consistent with the concerns and needs of astrological signs. Lithotherapists recommend its use to gemini , to scales , to sagittarians and to cancers .

Finally, to conclude this article, know that the opal wedding are known as the celebration of 21 years of marriage .

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You will find on the ousia shop , green opals , opaque white opals and sublime noble opals from Ethiopia, from the Welo region .