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!

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.

Jewelry Trend Watch: East-West Settings

If you’re looking for a style that takes traditional in a different direction, check out the east-west setting. It’s the lastest jewelry trend that places the gemstone horizontally vs. the classic vertical setting. Whether the cut is oval, pear, marquise, or emerald, the east-west setting will be noticed!

We’re spotlighting a few designs from our AGS members that feature this eye-catching setting. Click on the images to get a closer look.

 

 

Looking to see some east-west set jewelry in person, visit an American Gem Society credentialed jeweler near you: www.ags.org/findajeweler.

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.

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.

Bring on Spring: Be Inspired by the Colors of the Season

“April hath put a spirit of youth in everything.” – William Shakespeare

Now that spring has arrived, we look forward to the signs of renewal. From fastidiously cleaning our homes and joyously changing out our wardrobe to reconnecting with family and friends for a spring holiday or wedding. It’s easy to love this time of year!

Even our jewelry is complementing the seasonal spectrums, with soft pastels and bright, happy colors. Here are some spring-inspired styles from a few of our American Gem Society (AGS) members.

 

We’ve all got that extra spring in our step thanks to the warmer weather and the chance to don the colors of the season in our homes, wardrobe, and fine jewelry! Search for an AGS-credentialed jeweler near you and they’ll help you find the perfect piece for any springtime occasion.

Garnets – Warm, Strong & Mysterious

By Isabelle Corvin, CG, Staff Gemologist at Panowicz Jewelers

Happy birthday, January babies!

Born the first month of the year, you get to start with a celebration of life. Ignore the dreary weather with a warm garnet as your birthstone!

A somewhat under-appreciated jewel, garnets hold a mystery and allure all their own. A group of closely related species, the garnet family of gems is vast and varied.

  • Everything from classic Pyrope and Almandite; the traditional reds, from dark to light, sometimes slightly brownish, to Rhodolite, a shy little stone with flirty edges of purple added to red
  • Then there are members like cool Tsavorite, the vivid to minty green rebel striking out and being different
  • Demantoid, the fun-loving gem in yellowish-green colors with fire like a diamond
  • Don’t forget Spessartite, the flashy and robust gem of bright orange
  • And Hessanite, a softer, “honey” color, often hiding amid the rest of the group
  • In fact, Garnets come in every shade BUT blue!
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Garnets in a variety of colors by Underwood’s Fine Jewelry.

Throughout history, garnets have been known as stones of warmth, strength, and mystery. The most common color, a deep red, was popular in many cultures and used in a variety of items—not just jewelry.

It was the most popular stone for adornment and inlays in the late Antique Roman period, and a strand of garnet beads was found in an Egyptian tomb dating back some 5,000 years.

It was said to be a stone of valor, that wearing it as an amulet gave someone strength and enhanced bravery. It was also connected with love due to the color, and no surprise, it was associated with the element of fire.

There is a legend that Noah didn’t use lanterns in the Ark—he hung garnets. They were said to glow due to their inner fire and throughout the entire voyage of the ark, stayed lit.

In more modern times, garnets are associated with Capricorn, the zodiac sign, and are believed to help with strengthening both emotions and the physical.

In a more science-based outlook, garnets are used as abrasives in many fields.

Garnets are one of the few gems that display their full, natural color; no treatments are done to enhance or alter them.

Depending upon the type of the garnet, they can be found in many locations around the globe. They usually form in a cubic structure, like squares piled on top of one another.

Garnets are anything but plain or ordinary, and with a wide range of colors to choose from, there’s a member of the family that’s right for everyone. It shines on after years and carries with it ancient history.

It’s a pretty bauble and a treasured talisman. No matter how melancholy the weather may be this time of year, you can rest assure that a garnet will brighten up your day!

The American Gem Society’s Director of Marketing wanted to show off her favorite pieces of jewelry which happen to feature garnet! The earrings and ring were both designed by AGS member, M.J. Christensen.