Introduction to Opal - Properties, History and Symbolism

One of the beauties of the world of gemology is the diversity of gems that nature produces. But let's be honest: few have the same tradition, impact and history as Opal. This gem, although semi-precious, commands some of the highest prices per carat. In this guide, our aim is to look into the world of opal and explore its properties, history and most important of all, its symbolism.

What is Opal?

Opal is a semi-precious gem that has a significant water content in its structure. Specifically, it has a chemical structure SiO2.nH2O and is a mineraloid. A mineraloid is a mineral that does not have a formal atomic structure; unlike the majority of other minerals found in nature. It is primarily composed of hydrated silica, a form of silicon dioxide but with additional water in its structure. The remaining 10% of the opal is water.

How is opal formed?

The majority of opals are formed in Australia, with a significant percentage also coming from Ethiopia and Mexico. Opals are formed differently, and each of these three nations has different opal formation methods. Australia, being the world's largest supplier of opal, tends to be the one we discuss the most in the jewelry trade.

When water hits the ground, it moves downward through the earth and combines with silica. This solution of silica and water penetrates cracks and voids below the surface, creating deposits of silica over millions of years as the water evaporates during the summer. The stone we know as opal is formed.

Cracks in the ground, like the one above, are where silica deposits form opals over millions of years.

What types of Opals are there?

Although a diverse family of gemstones, opals can be divided into two main categories: common and precious opals. The play of colors within the gem is what determines its classification and therefore its value.

What do we mean by color scheme?

Take any shiny opal and you will see different colors and lights reflected. This reflection of endless colors is known as "color play" and is found primarily in Australian and Ethiopian Welo opals. When light enters the surface of the opal, it is reflected in all directions by the internal structure of the gem.

What are the colors of opals?

Almost any color for the body but it can be quite specific for the color scheme, where yellow and red are most visible.

What is the symbolism of Opal?

• Healing stone thought for once cute eye disease;
• Believed to be a stone that brings good fortune, especially wealth;
  Used in some cultures to help avoid suffering from the evil eye.

View our opal collection