Opals are unique types of gemstones available in a range of colors. These gems are formed from hydrated amorphous silicon dioxide to make remarkable treasures which can be used to create various types of jewelry.

The opal gets its name from the Sanskrit word for ‘stone’. It is not categorized as a mineral, but instead as a mineraloid, due to its amorphous form.

Opals are the national gemstones for the country of Australia. 97% of all opals in the world are produced in Australia.

The Three Different Types of Opals

three types of opal

While opals have several different trade names for their various colors, they can be divided into three categories. The 3 types of opals are: precious opals, fire opals, and common opals.

Precious opals have the ability to diffract light, which provides the stones with a shimmering, rainbow appearance that changes with every angle. This is known as ‘play of color’.

Fire opals will have more of a vivid background or body color, although they can feature some slight color play at times.

Common opals have an opaque appearance. They lack any type of color play and are usually not translucent.

Opals are also known by various trade names that help describe their appearance. Some of the most common include the Black Opal, Fire Opal, Pink Opal, and the Harlequin Opal.

Factors that Determine the Value of an Opal

There are several factors that help determine the value of an opal. It is a good idea to learn as much as you can about these properties before you decide to start an opal collection. Failure to do so could cause you to end up with stones that lack their value and worth.

Color

white opal

Opals come in many colors such as white, pale yellow, brown, black, pale red or gray. The diffraction of the stone can cause various flashes of colors that can be seen in the color play of the stone. These splashes of color can be violet, blue, green and yellow, among others.

Opalescence is another color variety that is often a shade of blue, yet it can also appear in other colors as well. The saturation, the play of color and transparency help configure the value of an opal.

Clarity and Luster

assessing the opal's clarity

All opals will feature some internal fractures or issues such as patches. These gemstones can range from transparent to opaque and every form of clarity or luster in between. An opal will often have a waxy appearance which helps with the play of color and the translucence.

Cut and Shape

opal shapes and cuts

Opals are commonly cut into a shape that will help preserve their overall weight. They may be cut with a low or high dome, based on each stone’s color bar.

Some opals are faceted, like the Fire Opal. These stones are featured in rings, necklaces and other types of jewelry in various shapes, sizes and cuts, such as rounds, cushions, and ovals. They can also feature conventional cuts like hearts or marquises.

Treatment

opal treatment

The treatment of an opal will also determine its value. Most opals are untreated, however, there may be some that are treated with wax, oil, or plastic to enhance the stone’s vivid color and stability. The stone may also be layered as doublets or triplets for even more stability.

Smoking is a common treatment option that is becoming more popular these days. This treatment will darken the body color of the stone while it enhances the color play. This process is often seen in Ethiopian opals.

You can also find synthetic opals that include plastic in their treatment. These are known as imitation opals since plastic is not found in the natural stones, and they are obviously the least valuable.

How to Care for Your Opal Jewelry

cleaning the opal

All the types of opals have high-water content which causes them to be very delicate. If you leave one in a dry area, it will eventually crack or fade. Those who live in dry climates should take precautions if they own pure opal jewelry.

It is a good idea to store opals in a sealed plastic bag with a damp cloth. This will help prevent the stones from damage because of dehydration. Opals may also change colors because of sudden changes in temperature, and scratch easily since they are a soft stone.

Always clean opals using a soft cloth and mild soap or detergent. Remove all types of opal jewelry before engaging in an activity where the stone may be damaged.

Choosing the Right Opal for Your Jewelry Collection

Choosing the perfect opal for a custom ring or necklace can be difficult since there is such a large variety of stone types and colors out there.

These gems are often overlooked by jewelry enthusiasts because of their opaque appearance. However, you can find opals that are bursting with a rainbow of color if you know which type of stone to look for.