Opal is known for its distinctive appearance and has been a popular gem used in jewelry for centuries. As official gem for the 14th wedding anniversary and October's birthday stone, opal is a highly sought after gem.
What is Opal?
Opal is a natural hardened silica gel condensate containing 5-10% water. Opal belongs to the opal group in mineralogy. It contains two kinds of gemstones, variable color and constant color. It is an amorphous silica containing water.
If the silica spheres in the opal are uniform in shape and size, then the gem will show a play of color, which is what makes it so unique. Some say the colors look like lightning, galaxies or fireworks trapped inside a stone.
The name "opal" is said to be derived from the Sanskrit word Upala, meaning "gem" or "gemstone" and later in the Greek word "opallios," meaning "to see a change in color."
Although opals are not quite hard gemstones, they have become so popular in jewelry over the years. They are also pretty popular in engagement rings because of their beauty and rich appearance.
Types of Opal
If you are considering buying opal for an engagement ring, you need to understand the different types of this gem. These types fall into two categories: "precious" and "common." Although precious opals command high prices and are used in jewelry, common opals are used for a variety of other purposes because they are too soft.
Precious Opals
- Black Opals
These are the rarest and most valuable of all opal stones. Black opals have a dark color, and they display all colors of the spectrum. The contrast of the color with the black background gives the gem a gorgeous, rich look.
- Crystal Opals
These are translucent stones that allow light to pass through them when illuminated. It was named "crystal opal" because its translucency makes it look like a crystalline material. However, crystal opals are not actually crystalline in structure.
- White Opals
These stones also known as "milky opal," these gems have a soft look and light body tone. They display any color of the spectrum in stunning colors.
- Boulder Opals
Boulder opal is formed from sandstone or ironstone, which is connected to the parent rock. It is different from other precious opals in that it is slightly harder and much more stable.
Common Opals
The common opal, also known as a "potch," is one that does not display any play-of-color or iridescent colors commonly found in precious opal. Although the two types are made of the same mineral, the silica spheres in potch are all of different sizes and mixes, while in the precious opal they are uniformly and neatly aligned.
Post time: Aug-29-2022