Fascinating Phenomena in Gemstones

There are several varieties of gemstones that display optical phenomena, which describes the many ways light interacts with the structural features or inclusions (internal characteristics) in the gemstone. Often these gemstones will be fashioned in a particular way that best displays these effects.

The science of optical phenomena can be fascinating, although the mystery and allure of these effects are what initially attract us! Below are six of the most familiar (and magical) displays of optical phenomena in gemstones.

Play-of-Color

Play-of-color is created by a combination of diffraction and interference, and is the result of the microstructure of opal: the chameleon of a thousand colors and October’s birthstone!

Opals are made up of many layers of small, stacked spheres of silica. These spheres diffract light, splitting it into a spectrum of colors. The layers of these spheres create interference allowing certain colors to dominate, depending on the angle the opal is viewed.

Asterism

Asterism, or stars, relates to the four- or six-rayed star pattern of light produced by the fibrous inclusions, elongated needles, or growth tubes in a gemstone. This singular, celestial-like phenomenon is best seen in a gemstone cut en cabochon.

 

Chatoyancy

Chatoyancy [sha-TOY-an-cee] is also known as “cat’s eye.” Fine needle-like or fibrous inclusions within the gemstone are what causes this effect. Again, stones fashioned as cabochons display this effect the best.

 

Color Change

A small number of gemstones display the color change optical phenomena. Depending on the lighting environment, the color change appearance can vary due to the shifting wavelengths. The technical term for this is photochromism or photochroism; “color-change” is a lot easier to say!

The best-known color changing gemstone is alexandrite. When viewed in sunlight, it appears greenish. When placed under incandescent light, it appears reddish. Other varieties of color-changing gemstones include sapphire, garnet, spinel, diaspore, and tourmaline.

 

Adularescence

Adularescence is the phenomenon typically seen in moonstone, which is a member of the feldspar family. It produces a billowy soft blue to milky white light that appears to move across the gemstone. This occurs when light hits the alternating layers of albite and orthoclase, which are two differing forms of feldspar within the gem.

The layers of feldspar interfere with the light rays causing them to scatter and the eye to observe adularescence. The effect is best seen when the gemstone is cut en cabochon [en CAB-ah-shawn]—that is, with a polished, domed top and a flat or slightly rounded base.

 

Labradorescence

Labradorscence [lab-ra-dor-es-cence] is an optical characteristic often seen in labradorite. The effect is a spectacular play-of-color that is metallic or iridescent, displaying blue, green, red, orange, and yellow. This is an interference effect within the gemstone caused by internal structures that selectively reflect only certain colors.

 

Are you ready to see some of these displays in person? Visit an American Gem Society (AGS) jeweler near you and ask to see some gemstones that exhibit optical phenomena!

Color Comes Into Play with October’s Birthstones

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Opal and tourmaline from Gem 2000.

When it comes to color choices, October’s birthstones give you some amazing choices. Whether you choose opal or tourmaline, you’ll get a display of exciting and intense colors, making them popular choices for jewelry designers and collectors.

Opal

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.

Each opal is totally unique, like fingerprints!! To get a really good look at the opals in these designs, click on the images below for a larger view.

Tourmaline

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.

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.

 

If you are shopping for opal or tourmaline jewelry, click here to search for an American Gem Society (AGS) credentialed jeweler near you.

 

Fancy These Four Fancy Shape Diamonds

The time has come in your relationship to finally pop THE question. Various thoughts are now running through your mind, like how to ask, where to ask, and when to ask. And then it dawns on you: what type of ring should I choose?

If a traditional round brilliant diamond is too traditional for your taste, consider one with a different shape. Fancy Shaped or Fancy Cut diamonds (as they are also known) are beautiful and sometimes even more affordable than the traditional round brilliant. These geometric works of art are created by diamond cutters who are master craftsmen with a cutting wheel.

Fancy shaped diamonds can also come with diamond grading reports so that you can best understand the diamond’s characteristics.  AGS Laboratories pioneered the light performance cut grade for fancy shapes, which means between the diamond cutters and AGS Laboratories, you now have more options of beautiful diamonds to choose from.

Here are four different fancy shapes to consider when shopping for the perfect ring.

Pear

The pear-shaped diamond has become a popular fancy shape among celebrities and modern brides who are looking for an elegant, eye-catching engagement ring. This beautiful rose gold ring from Tacori features a pear-cut diamond framed by a pear-shaped halo.

 

 

 

Emerald

Emerald cuts are another great alternative. Take this showstopping emerald cut from Harry Kotlar, which is flanked by two spear-like diamonds.

 

 

 

Oval

Ovals are classic diamonds that are just a bit more cheeky than a round brilliant. They say, “I have a classic style, with a bit of an edge.” Just like this stunner from Valentina Diamonds.

 

 

 

Marquis

The long, narrow shape of this fancy cut is often credited for making the finger appear more slender. Check out this diamond halo marquis-cut engagement ring from Norman Silverman Diamonds.

 

 

The right ring can be found with a little research and shopping around. One thing the right ring needs, though (besides the right person to give it to) is the right jeweler. Find the perfect jeweler here.

Quote-worthy Jewelry

We often share beautiful images of  American Gem Society members’ jewelry. Today, we wanted to take that a step further and give you a sneak peek into their passion for jewelry, the symbolism it represents, and the way it makes them feel. In some cases, we just wanted to give you a glimpse of their humor, with jewelry as their much-adored punchline.

To achieve all that, we asked these five members to give us a quote about jewelry, along with an image of one of their favorite pieces. Enjoy!

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Opal brooch from Paula Crevoshay.

 

Spinel pendant from Sharon Wei Designs

Pink tourmaline pendant from Sharon Wei Designs.

 

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Moonstone, sapphire, and diamond ring from Omi Privé.

 

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Custom-designed ring from Michaels Jewelers.

 

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Diamond engagement ring by Tacori.

To find some jewelry inspiration of your own, visit your local American Gem Society (AGS) jeweler. Ask your AGS jeweler if they have a personal saying or a favorite quote about jewelry! You can ask them to show you one of the above pieces or something that inspires you and your imagination. Visit ags.org/findajeweler.

Jewelers Mutual Presents: Your Birthstone Guide

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There’s something about birthstones that creates fascination, whether the focus is on their history and lore, or the emotional connection an individual may have with their birth month’s gem(s). In fact, the most searched topic on the American Gem Society website is “birthstones.”

Jewelers Mutual Insurance Group, in collaboration with the American Gem Society, has created a handy, go-to guide for birthstones. The guide features interesting facts about each birthstone and how to care for them. Click here to learn more!

The Merry Month of May

By Isabelle Corvin, CG, Staff Gemologist at Panowicz Jewelers.

“O, the month of May, the merry month of May, So frolic, so gay, and so green, so green, so green!” – Thomas Dekker, Author, (c. 1572–1632).

May is truly the month that really feels like spring, and what better gemstone to have as the birthstone of this blossoming month than an emerald?

 

There’s no other stone that can match the lush, vibrant greens of emerald, truly a springtime favorite. In fact, some people believe the emerald symbolizes renewal and goodness, and that it is a stone that will increase a couple’s love for each other.

The color of lovely springtime emerald can vary in all hues of green, sometimes with a tinge of yellow and others leaning towards the blue-greens. These stones can be light and airy, or deep and dark, and everything in between.

 

Not only that, but it can be highly saturated with this earthy color, making it bright and energetic, just like this time of year.

Emeralds have been prized gems throughout history. Egyptians used the stones for many purposes and claimed a magic slab of the gemstone had “all knowledge” engraved on it. In India, there’s a myth that tells of a firefly that crystallized into an emerald. The Aztecs likened the beautiful color to the plumes of god-like birds.

Those of you who own an emerald (or desire to have one!) are in good company; emeralds were Cleopatra’s favorite gemstone.

 

Emeralds are to be worn with care since they are a softer gemstone than others. But with proper treatment, these stones will last a lifetime.

Emeralds are mined in many locations around the world, from the famous mines in Colombia to the newer mines in Zambia, to others. The finest Colombian emeralds are delightfully bluish-green, richly saturated and stunningly clear.

This spring, while we watch the flowers bloom and the trees sprout, don’t forget your May babies—or their beautiful birthstone, emerald!

Jewelry images by credentialed AGS members. Visit ags.org/findajeweler to find an AGS jeweler near you.

 

isabelle

Isabelle Corvin is an AGS Certified Gemologist (CG) who is the Staff Gemologist at Panowicz Jewelers. Since she was 14-years-old, she knew she wanted to be a gemologist. Ms. Corvin also writes for Panowicz Jewelers’ blog.

Celebrate the Woman Who Means Everything

By Robin Skibicki

“Being a mother is about learning about strengths you didn’t know you had and dealing with fears you didn’t know existed.” – Linda Wooten, author.

When I was 9 years old, I asked my Mom on Mother’s Day why there isn’t a Children’s Day. Without hesitation, she responded in a kind but firm voice, “Honey, EVERY DAY is Children’s Day.” I knew that tone and I also detected that wasn’t the best question to ask at that moment.

Now that I’m a mom, I get it! In fact, I believe mothers truly need more than one day a year to call their own. How about once a month? The list of gratitude towards our mothers can be infinite, from the little things, like kissing a “boo-boo,” to jumping in with all her heart and soul to help us through a rough situation.

Nowadays, we realize that Mother’s Day isn’t just about mothers. The holiday extends to celebrate all the incredible women who have made significant contributions in our lives, helping us become who we are today. She can be a stepmom, mother-in-law, grandmother, daughter, daughter-in-law, aunt, sister, cousin, friend, teacher, or mentor.

If you are looking for a gift that is beyond special and significant for a fabulous female in your life, consider fine jewelry. They’re not only gifts that will make her smile (possibly with a glistening tear in her eye) once she opens it, but each day she wears it. She will treasure it for years to come and it will ultimately become a cherished heirloom.

The credentialed members of the American Gem Society (AGS) have got you covered for Mother’s Day. Here are a few ideas to get you started. If there is a design you like or have an idea of your own, contact an AGS jeweler near you!