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!

Corundum of Many Colors: Sapphire

As we turn our calendars to September, we start thinking of things like heading back to school, sipping on a pumpkin spice latte, and planning our fall fashions. For those celebrating a birthday in September, they’re thinking of their birthstone: sapphire!

Although sapphire typically refers to the rich blue gemstone variety of the mineral corundum, this royal gem actually occurs in a rainbow of hues. Sapphires come in every color except red, which would then be classified as ruby.

Trace elements like iron, titanium, chromium, copper, and magnesium give naturally colorless corundum a tint of blue, yellow, purple, orange or green, respectively. Sapphires in any color but blue are called “fancies.”

Pink sapphires, in particular, tow a fine line between ruby and sapphire. In the U.S., these gems must meet a minimum color saturation to be considered rubies. Pinkish orange sapphires called padparadscha (from the Sri Lankan word for “lotus flower”) can actually draw higher prices than some blue sapphires.

Due to the remarkable hardness of sapphires—which measure 9 on the Mohs scale, second only to diamond—they aren’t just valuable in jewelry, but also in industrial applications including scientific instruments, high-durability windows, watches, and electronics.

Sapphires make stunning gifts for anyone born in September or celebrating a 5th or 45th wedding anniversary, so be sure to visit an AGS jeweler. They will help you find that perfect gift, whether you’re seeking the classic blue or another shade from the sapphire rainbow.

Need some inspiration? View this collection of designs featuring the sapphire!

Four Fine Jewelry Trends for Spring 2019

Spring is here and we’re ready for some jewelry trends to help us celebrate this much-welcome change of season! Now that the weather is warming up, what’s hot? We’ve gathered some season-sensational (We just made that up!) designs from our AGS members.

Quite possibly the most quintessential symbols of spring are flowers, butterflies, and bees. Naturally, their likenesses are found in a variety of fine jewelry designs.

 

Next on the list is chains. Big chains. Little chains. This trend is an ode to the Eighties and they’re everywhere!

 

It’s been said that pearls never go out of style, but these aren’t your grandmother’s pearls! Modern designs have re-imagined the classic jewelry wardrobe staple.

 

The warmer weather has us looking towards the sky and the sea for a much-needed getaway! Both celestial and nautical-themed designs inspire us to seek the outdoors (and beyond) for our next adventure.

 

Are you ready to add a bit of bling to your spring wardrobe? Find an American Gem Society jeweler member near you at www.ags.org/findajeweler.

Living Coral: Pantone’s 2019 Color of the Year

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

pantone-livingcoralPantone has officially announced it’s 2019 Color of the Year as “Living Coral” (16-1546)!

This bold, energetic, and dynamic color is sure to liven things up for the New Year! Pantone calls Living Coral “sociable and spirited” and says that it is a nurturing color. It’s a blended hue of orange and pink, creating a bright spot in our everyday lives.

The first known written use of the word “coral” to describe a color was in 1513, and the use of “coral pink” was in 1892. The term “coral” for color has been used to described reds, oranges, and pinks, as well as mixed colors from those components.

Cheerful and shocking, coral lends itself well to all aspects of décor, graphic design, and fashion. In fact, you’ll find several gemstones that display this bright, bold, and beautiful color!

Padparadscha sapphire and Rhodochrosite match Living Coral almost perfectly, with their lively blend of just the right amount of pink and orange.

 

Padparadscha is a high-energy stone with an exotic look. The name comes from the Sanskrit word for “lotus.” And indeed, some lotus blossoms exhibit Living Coral excellently!

Rhodochrosite embodies the feeling of Living Coral with its color and the belief that it is a powerful stone for opening your heart once more. It is said to heal emotional wounds and be a guide for finding love.

Other gemstones that depict shades of Living Coral are additional sapphire colors, and some hues of topaz and spinel, as well as certain garnets.

 

Living Coral reminds us that the world around us is alive, filled with wonder and magic, if we only take a few moments to look. The color dives deep into our hearts, beckoning an appreciation for life’s moments and worthwhile memories.

According to Pantone, they chose this color for that very reason. In a world so immersed in technology, we all seek connections. Living Coral is a delight to the eyes and a light to the heart.

Happy New Year!

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.

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!

paula Crevoshay

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.

Setting our Sights on Sapphires

By Robin Skibicki

As we change our calendars to September, our sights are set on cooler weather, and on sapphires!

Sapphires are known for their beautiful blue hue, but they can also be found in a variety of pinks, yellows, and oranges, even peach, green, and violet colors. These colors are referred to as fancy sapphire.

One of the most sought-after fancy sapphires is the padparadscha. Its pink-orange coloration can be compared to that of a tropical sunset. Princess Eugenie, a cousin to Princes William and Harry, received an oval cut padparadscha sapphire ring for her engagement, bringing this rare gemstone into the limelight.

Omi-sapphire

Padparadscha sapphire and diamond ring by Omi Privé. This ring is the AGTA 2018 Spectrum Award Winner.

Sapphires can also display the celestial-like optical phenomena, asterism, adding the name “star” to this type of sapphire.

Suna-PinkStarSapphire-loose

Pink star sapphire cut en cabochon, by Suna Bros.

September babies are lucky to have a birthstone that comes in a variety of colors! Below are a few images from American Gem Society (AGS) members that showcase the chromatically-gifted sapphire. To find an AGS-credentialed jeweler near you, click here!

There is a Cure for the Summertime Blues

By Donna Jolly, RJ

As summer stretches out toward its final dog days, and the thermometer keeps bobbing toward the high end, you are probably feeling the need to cool down. We have some nice ice to help. As usual with us, it’s the jewelry kind of ice.

Let’s look at five amazingly lovely pieces of jewelry we’ve recently featured on our AGS Facebook page to help us take our minds off of the temperature.

First up, these blue topaz and peridot earrings, and blue topaz pendant, from Goshwara are as calming and cool as the ocean itself.

Goshwara

Staying with the light blues, we love this custom engagement ring from Tacori:

Tacori

Let’s keep the light blue theme going, with this big, beautiful zircon ring from Carizza:

Carizza

Straying from the lighter blues, let’s get a little deep, as in the deep violet hue of this Tanzanite beauty from United Color Gems.

UGCLast, but certainly not least, imagine this blue-green sapphire from Gem 2000 in the style of your choice. What would you do? A pendant? A solitaire ring?

Gem2000

To find any of these beauties, contact your local AGS jeweler here.