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

Opal-Tourmaline2

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.

 

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.

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.

Seeing Green: The Perfect Jewelry for St. Patrick’s Day

Blog article courtesy of the American Gem Society (AGS) member, Malak Jewelers. Featured photos were contributed by members of the AGS.

Art Deco emerald and diamond bracelet by Nash James.

Art Deco emerald and diamond bracelet by Nash James.

Throughout the world on March 17th, the streets fill with laughter, dancing, and most of all, the color green.  St. Patrick’s Day began as a religious feast day observing the death of St. Patrick. But now it has turned into a variety of festivals across the globe, celebrating Irish culture with parades, special foods, music, dancing, and a whole lot of green.

If you are at a loss for what green to wear, or just want to add more green to your outfit, here are four of the most well-known green gemstones that will add sparkle and color to your St. Patrick’s Day.

EMERALDS

Emeralds were first found in Egypt in 330 B.C. The name “emerald” derives from the Greek word smaragdos, which was a term used to refer to the greenest of gems. Emeralds can come in varying shades of green and some feature blueish hints. The green color comes from trace amounts of chromium and vanadium in the mineral beryl. Its color symbolizes the rebirth and renewal of spring, and that is why it is the birthstone for the month of May. It’s also a popular gem for the 20th and 35th wedding anniversary.

Emeralds are typically formed in six-sided prisms, so they are naturally suited for the emerald cut for jewelry. They are mostly found in Colombia, Zambia, Brazil, and Zimbabwe. North Carolina is also a minor source for emeralds.

PERIDOT

Peridot’s name comes from the Arabic term faridat which means “gem.” Peridots were referred to as the gem of the sun by the Egyptians because of its bright color, which ranges from light to dark green and yellowish green. Most commonly it is seen in pale olive but can be bright golden lime. The mesmerizing color comes from trace amounts of iron within the mineral.

Peridot is the birthstone for August and the gem for the 16th wedding anniversary. The leading producer of peridots is in the San Carlos Indian reservation in Arizona.

ALEXANDRITE

The first alexandrites were discovered in Russia in the 1830s. The gemstone is named after Czar Alexander II. It is often described as “emeralds by day and rubies by night” because it is blueish, green in the daylight and purplish, red in incandescent light. Alexandrites change color because they are a rare variety of the mineral chrysoberyl. This gem provides dramatic proof of how a light source can affect the color of gemstones.

If you know of any June babies or a happy couple celebrating their 55th wedding anniversary, then alexandrite makes a treasured gift!

JADE- JADEITE

The names “jade” and “jadeite” come from the Spanish phrase piedra de ijada meaning, “stone of the lions.” They may sound similar, but they have totally different chemical, optical, and physical properties, with jadeite being the more valuable of the two.

Most of the classic jade (nephrite jade) comes from China, whereas Myanmar is the main source for jadeite. Jadeites are held in high regard throughout the Asian culture. And in China, nephrite jade is a symbol for purity, good luck, and prosperity. Jadeites come in varying shades of green. The most valuable jadeites are pure “imperial” green, which equals the intensity of emeralds.

 

Malak Jewelers
Malak Jewelers is Charlotte, North Carolina’s premier direct diamond importer, supplier of loose diamonds, and custom design jewelry

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!
UnderwoodsFineJewelry-garnets

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.

 

Six Displays of Optical Phenomena in Gemstones

By Robin Skibicki

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! In this article, we’ll discuss six of the most familiar (and magical) displays of optical phenomena in gemstones.

Adularescence

Adularescence is the phenomena 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.

 

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.

 

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.

 

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!

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.

 

Are you ready to see some of these displays in person? Visit a credentialed AGS jeweler near you and ask to see some gemstones that exhibit optical phenomena!