Guide to Opal Gemstone - The Birthstone of October


Opal is a translucent or opaque gemstone that is designated as the birthstone for the month of October. It is considered to be one of the most beautiful gemstones and famous for its kaleidoscopic interplay of colors. Sometimes it is also referred to as the Queen of Gemstones. Its uniquely incomparable and phenomenal beauty will never fail to lure you. It has the power to steal the heart of anyone who beholds it. 

Opal stone has special significance in the life of those born in October. This is why it is famous as the birthstone of October. According to Astrological belief, this magical precious or semi-precious gemstone is a symbol of hope and purity. It brings happiness and love to the life of its wearer. It strengthens the relationship

There are several other benefits of wearing Opal gemstone. The best and most preferred way to possess this beautiful gemstone is wearing an Opal gemstone ring. You can also consider other opals such as opal necklaces and earrings.  

History of Opal Gemstone

Opal gemstones have a fascinating history. It was first found on the riverside of Australia in 1877. Australia produces over 90% of the world’s precious opal gemstones. Koroit, Lightning Ridge, Quilpie, Coober Pedy, and Yowah are the most famous mining areas in Australia where opal stones are found. Opal is the national gemstone of Australia. Other sources of opal gemstones are Ethiopia, Virgin Valley (Nevada), Mexico, Spencer (Idaho in the US), Canada, Hungary, Czech Republic, Turkey, Slovakia, Nicaragua, Guatemala, and Brazil.

Types of Opal Gemstone

Opal is a mineraloid gemstone and a form of hydrated silica (SiO2·nH2O). It is typically semi-transparent stone and shows many small points of shifting colors when contacted with light. It comes in many colors - red, white, yellow, green, orange, blue, green, brown, pink, colorless, etc. The common color available in the market is white or cream.

There are two notable types of natural opal gemstone. There are precious opal and common opal.

Precious Opal

Precious opal aka opalescent opal shows the kaleidoscopic interplay of internal colors. The stone is composed of silica elements in microscopic spheres of 150 to 300 nm in diameter in a hexagonal or cubic close-packed lattice. You will be amazed by the best beauty of the precious opal gemstone in the light. In the presence of light, the opal stone reflects colorful lights through its microscopic spheres, creating the prismatic effect. The reflection of the light makes opal very appealing.

Further, precious opals have been classified into two groups namely while or milky opals, and black opals.

White/light opal: White opal is found in the white or light basic color. These stones make up the bulk of precious opals. They are predominantly mined at Coober Pedy and Mintabie, (South Australia)

Black/dark opal: Black opal is found in dark colors such as dark blue, dark grey, grey-black, dark green, and deep black. Deep black opal is a very rarer type of precious opal.

Boulder Opal: Boulder opal is one of the most popular varieties of precious opal. It has a host of rock-forming naturally as part of the gem. Just a thin vein of precious opal is present in boulder opal. The demand for boulder opal is high and hence it is extremely valuable. The color of the boulder opal can be dark or light depending on the appearance of the stone when viewed from the surface.

Matrix opal: Matrix opal is a porous stone. The color enhancement of this stone is done by deposing black carbon by chemical treatment in the pores.

Common Opal

Common opal does not exhibit the iridescences. But it often shows a hazy-milky-turbid sheen of light from within the stone. In gemology, this phenomenon is strictly defined as opalescence. The hazy milky sheen displayed by the common opal is a form of adularescence. Common opal is also known as potch opal.

Other Verities of Opal Gemstone

There are some other verities of opal stone. They are Fire opal, Girasol opal, and Blue opal.

Fire Opal

Fire opal is another notable type of opal gemstone. It is relatively a transparent gemstone with vivid yellow-orange-red color. It rarely exhibits iridescence

Hyalite Opal: Hyalite is a form of opal. It has a glassy and clear appearance. This stone may display an internal play of colors in the presence of natural inclusions. Other names of hyalite opal are Muller's glass, jalite, and water opal.

Girasol Opal

Girasol opal is also a type of hyalite opal with a transparent to semitransparent appearance. The stone exhibits a bluish sheen that follows the light source around. When the stone is cut properly, it displays an asterism or star effect.

Blue Opal

Blue opal is a semi-opaque stone to opaque blue-green stone. It is also called Peruvian opal because it is mostly found in Peru. The stone does not exhibit the play of colors.

Triplet Opal

Triplet opal is a popular type of composite natural opal. It has three layers. The lower layer is backing materials, the middle layer is opal slice and the top layer is a domed cap of clear quartz or plastic on the top. It is one of the cheapest types of opal gemstones. In the process of forming a triplet opal, the natural opal is infused with the quartz and is made thinner. The top of the triplet opal is glued with the protective crystal dome.

Doublet Opal

Doublet opal is a composite natural opal. It is a combination of natural opal and artificial material. In the formation of doublet opals, a layer of precious light opal is placed and glued with, to strong backs or black material, simulating black opal. Doublet opals are thinner than the natural opals. They are more expensive than triplet opals because more opals are used in the formation of doublet opals.

Benefits of Wearing Opal Birthstone

Opal is the birthstone for October and has several astrological benefits in the lives of their wearers. Key benefits are:

  • Opal strengthens memory, brings originality, and increases energy.
  • It helps in expressing one’s true self and understanding your full potential.
  • Opal is also known for healing properties. It is said that it helps to fight infections and fevers.
  • It purifies the blood and kidneys, helps to regulate insulin, and to eases childbirth.
  • The gemstone is associated with love and passion and help in strengthening relationships.
  • It also helps in gaining name and fame in the society along with gaining money.
  • For artists, opal stone results in numerous benefits.

In Conclusion

Opal is truly a magical and beautiful gemstone that can benefits a lot, especially for the people who are born in October. If you are looking for beautiful opal gemstone jewelries then Geoffrey’s Diamonds is the best place to buy the same. And you must take the utmost care of your opal gemstone jewelry once you have purchased it. We recommend you to keep opal jewelry away from prolonged sunlight exposure.