top of page

The Wonder of Opal

There is no other gemstone that displays flashes of reds, blues, greens, and yellows in a singular source. That is why Opal has been revered ever since it was first discovered! Last week we dispelled the myth that Opal is bad luck so that we have room to talk about the uniqueness of fine Opal!

Opal doesn’t have a crystal structure like faceted gemstones which is why it is cut, fashioned, and set into jewelry pieces very differently. Its mineral type is a hydrated silica and contains up to 20% of water. Opal is formed in ancient sea-beds or in places where rain soaked deep into underground rock taking dissolved silica with it. When most of the water dried up, the silica formed opal in cracks and layers between the sedimentary rock. I have seen clam shells and petrified wood that had layers of opal as well!

Play of Color: When you see rainbow colors flashing in an Opal, that is called play of color. When the sub-microscopic spheres of silica are stacked up nicely like ping-pong balls in a box, the play of color can be vibrant and varied! The less organized and stacked those spheres are, the less color you will see from an Opal which is where the class of common Opal comes in. Common Opal is hydrated silica that does not contain play of color, like much of the reddish orange Mexican Opal.

According to the Gemological Institute of America, experts divide Opal into five distinct groups.

  • White or light opal: Translucent to semitranslucent, with play-of-color against a white or light gray background color, called bodycolor.

  • Black opal: Translucent to opaque, with play-of-color against a black or other dark background.

  • Fire opal: Transparent to translucent, with brown, yellow, orange, or red bodycolor. This material—which often doesn’t show play-of-color—is also known as “Mexican opal.”

  • Boulder opal: Translucent to opaque, with play-of-color against a light to dark background. Fragments of the surrounding rock, called matrix, become part of the finished gem.

  • Crystal or water opal: Transparent to semitransparent, with a clear background. This type shows exceptional play-of-color.

Much of the world’s Opal comes from Australia as it is an ancient sea-bed, while Ethiopia has become a reliable source as well, but it has limitations. Most of the Opal coming out of Ethiopia has an additional property called hydrophane. Hydrophane Opal absorbs liquid very quickly and sometimes does not release it. The liquid adds carat weight to the Opal and dilutes the color of the Opal. When Ethiopian Opal is lying directly on skin, like in a pendant, body oils are absorbed too, and it can permanently change the Opal. Mexico and Brazil are other sources of Opal along with the United States. Parts of Idaho and Nevada contain Opal, but the consistency has not been reliable over the years.

One the things I find fascinating is that no two Opals are alike! It is definitely for the person who wants something different that no one else has! I find that each Opal can be like looking into a different universe. I bought my favorite Opal because I knew I would never see another one like it, and I didn’t want it to haunt me the rest of my life as the one that got away. I’m taking my time designing the pendant I want it to go in!

Whether you are shopping for an engagement ring, anniversary gift, birthday celebration, or just because, I can help you navigate and give you the personal touch you deserve! Why shop with the crowd if you don’t have to? Book your private appointment with me!

9 views0 comments

Recent Posts

See All


bottom of page