The name “opal” derives from the Greek Opallos, meaning “to see a change (of color).” They range in color from milky white to black with flashes of yellow, orange, green, red, and blue. An opal’s beauty is the product of contrast between its color play and its background.
Opal is a formation of non-crystalline silica gel that seeped into crevices in the sedimentary strata. Through time and nature’s heating and molding processes, the gel hardened into the form of opals. The opal is composed of particles closely packed in spherical arrangements. When packed together in a regular pattern, a three-dimensional array of spaces is created that gives opal its radiance.
Approximately 90 percent of the world’s precious opal comes from Australia. The following are other countries that produce precious or fancy varieties: Brazil, Mexico, United States, Hungary, Peru, Indonesia, Honduras, Guatemala, Nicaragua, Slovakia, Czech Republic, and Ethiopia.
Like fingerprints, each opal is totally unique! To get a really good look at the opals in these designs, click on the images below for a larger view.
Since tourmaline is available in a wide variety of colors, it is ideally suited to almost anyone’s taste. It is known for displaying several colors in the same gemstone. These bi-color or tri-color gems are formed in many combinations; the gemstones with clear color distinctions are highly prized.
One multi-color variety is known as watermelon tourmaline and features green, pink, and white colors bands. To resemble its namesake, the gemstone is cut into thin slices having a pink center, white ring, and green edge.
Tourmaline is found in many localities including Brazil, Afghanistan, East Africa, and the USA.
The following designs feature the varying hues of tourmaline. Click on the images to see a larger view.
On behalf of everyone at AGS, we send our best wishes to those celebrating a birthday or anniversary in the month of October!
If you are shopping for opal or tourmaline jewelry, search for an AGS credentialed jeweler near you: www.americangemsociety.org/en/find-a-jeweler.