May’s birthstone, emerald, is aptly named the gem of spring. Its vibrant green color evokes a lush garden. In fact, inclusions in emeralds are sometimes called an internal “jardin,” the French word for “garden.” The most desirable emeralds range from bluish green to green with vivid color saturation.

If you’re considering an emerald purchase, GIA’s Emerald Buying Guide puts all the information you need at your fingertips, including what quality factors to look for and an explanation why the most common cut of emerald is, appropriately, the emerald cut. Bookmark and share!

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Composed of a single element—carbon –and formed under extreme temperature and pressure, diamond’ remains one of the world’s most coveted gems – and the birthstone for those lucky enough to be born in April.

GIA’s Diamond Buying Guide provides you with the insights you need to buy wisely. Use the guide to learn about the GIA 4Cs: color, clarity, cut, and carat weight, get caring and cleaning tips, and even watch a video on how to choose a diamond. We hope you like it!

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March’s aptly titled birthstone, aquamarine, grows in gorgeous crystals and sparkles like the ocean on a sun-kissed day. But do you know what to look for when shopping for aquamarine?

This month’s Aquamarine Buying Guide is all about aquamarine with fun facts, practical tips, and answers to frequently asked questions. Enjoy, and don’t forget to pass it along to your fellow gemstone lovers!

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Known for its majestic purple color, amethyst is the gemstone of choice for those born in February. Breathtaking and surprisingly affordable, it’s also the most valued variety of quartz. If you’re in the market for this February birthstone, GIA’s Amethyst Buying Guide has tips and advice on what to look for, including amethyst quality factors.

Share our Amethyst Buying Guide with the February babies you know!

Click the buying guide image to see a larger view. Bookmark and share!

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January’s birthstone, garnet, is known for its impressive variety of eye-catching colors, which can be almost any color of the rainbow. Garnets occur in green (demantoid and tsavorite), orange (spessartine), red (almandine and pyrope), and purplish red (rhodolite), plus a few rare garnets even change color under different types of light. But color is far from a garnet’s only attractive feature.

GIA’s Garnet Buying Guide offers key pointers on what quality factors to look for, and helps you differentiate between some of the garnet varieties, for example two of the green garnets: tsavorite and demantoid.

Click the garnet buying guide image to see a larger view. Bookmark and share!

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Those celebrating December birthdays are fortunate to have a few birthstones to choose from – zircon, tanzanite, blue topaz and lapis lazuli, among them. But one of the best known and most loved December gems is turquoise, a gem that has been mined and used for thousands of years.

Jewelry found in ancient Egyptian tombs dating to 5500 BCE give turquoise the distinction of being one of the longest-loved gems in history. Many in the U.S. associate turquoise with Native American jewelry, but the gem is also commonly found in China and beloved by designers and collectors around the world.

One of the reasons collectors love this gem is because its appearance can have so much variation. Not all turquoise is turquoise! Turquoise is colored by copper, which creates an array of colors from intense blue to greenish blue to avocado and lime green. The gem’s color can be an evenly distributed medium blue, appear mottled, or display matrix. Matrix is the remnant of the host rock in which the turquoise formed and appears as splotches or veins.

The most prized turquoise color is an even, vibrant blue sometimes called “Persian blue” in the trade, as seen on the right. The stone on the left shows a wonderful example of matrix veins referred to as spiderweb turquoise

Turquoise is most often cut into cabochons, smooth domed shapes that are best suited to show off the stone’s color and any matrix. However, designers also use turquoise in jewelry inlays, as seen in this ring.

This white gold ring by Andrew Sarosi, set with diamonds and turquoise from the Sleeping Beauty mine in Arizona, shows the versatility of turquoise as the backdrop for the diamond detail. Image courtesy of Andrew Sarosi, L.A., Ca.

Turquoise rough is also fashioned into round or oblong beads or tumbled into “nuggets”.

This one-of-a-kind multi-strand necklace of turquoise and gold nuggets, created by Denise James, shows a more unusual use of turquoise in its rough form. Courtesy Denise James.

If you own (or hope to own) turquoise jewelry, there are a few things to keep in mind. Natural turquoise is porous, and its porosity makes it a candidate for treatment to alter its color and improve its durability. The gem can be discolored by chemicals, perfume, cosmetics, and even natural skin oils, so remove turquoise jewelry when cleaning or applying products to your skin.

When needed, clean turquoise with warm, soapy water; never use steam or ultrasonic cleaners. More on the care and cleaning of turquoise can be found on our Gem encyclopedia.

With the right care, fine-quality turquoise is quite durable, and jewelry fashioned from the gem will last generations.

Do you have a December birthday? You actually have a choice of birthstones: do you prefer the unique look of turquoise, the fire of zircon, or the lovely rich-hued tanzanite?

**White gold Sleeping Beauty turquoise earrings in main image courtesy of Andrew Sarosi, L.A., Ca.

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As the majority of the country heads into cooler temperatures of late fall/early winter, November’s birthstone, citrine, provides a much needed burst of sunshine. The warm, sunny color of this popular gemstone inspired its name, derived from the French word “citron,” meaning “lemon.” Its color ranges from saturated yellow to  reddish orange to pale  yellow.

Citrine is part of the mineral  species quartz, along with sibling gemstones amethyst, rose quartz, smoky quartz, rock crystal quartz and tiger’s-eye quartz. Much of the citrine on the market today is actually amethyst that has been heat-treated to turn it  yellow. Occasionally, you will hear citrine referred to as topaz; however, topaz  is a different mineral.. Both citrine and topaz are birthstones for November, and the colors of  yellow topaz and citrine can easily be confused.

A 214.91 ct citrine, cut by Michael Dyber.

Like all quartz gems, citrine is readily available and affordable, including very large-size stones.

The warm hue of citrine is commonly paired with polished, yellow gold, as seen here:

Inspired by the stars and the cosmos, this “Pluto” ring has two citrines set in gold. Gift of Patricia MB Gotthif.

Its sunny color is also a bright addition to multi-colored designs, and can be frequently found in a bouquet of gems including amethyst, topaz, peridot, and tourmaline.

Group of five cut citrines. Ranging in color from yellow, orange and brown.

Most citrine is mined in Brazil, especially from the state of Rio Grande do Sul. However, large amounts of amethyst and citrine have also been found in the Anahí mine in Bolivia, as well as Africa.

With a hardness rating of 7 on the Mohs scale, and good toughness, citrine is durable and will hold up to everyday wear.  However, high heat can cause color loss so you do not want to expose it to sunlight for extended periods of time. Cleaning is simple; just use a mild dish soap and warm water.  It’s an easy-to-care-for, affordable, and distinctive gemstone, making it popular for those with November birthdays (and many others as well).

Suite of citrines. (C) ICA

Do you have a birthday this month? Do you think citrine looks best standing alone, or do you prefer it paired with other gems to create a multi-colored look?

*At top Cartier citrine and diamond bracelet. (C) GIA & Tino Hammid

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The October birthstone, opal, is noted for its individuality, magic, and mystery. Its unique display of flashing rainbow colors is unlike any other gem, and has been compared to volcanoes, galaxies, and fireworks.

Throughout history, its intense visual qualities have made it a source of supernatural beliefs.  Bedouins believed that opals contained lightning and fell from the sky during thunderstorms. Ancient Greeks believed opals guarded them from disease. They’ve even been attributed with the power to preserve blond hair!

An opal’s value is determined in part by its background  color. A darker base with vivid flashes of color is the most desirable, and opals with dark gray to black base color are the most valuable. One famous black opal is the 700 carat stone Napoleon gave his wife and Empress Josephine de Meauharnais called “The Burning of Troy” because of its red flashes against a black  background color.  A more  affordable type of  opal has a white  to medium gray background color, called white opal.

Black opals, like this 29.85 carat gemstone from Australia, are prized for their rarity and fiery color. Courtesy of Mariora, Surfers Paradise, Australia

Another key factor in determining an this gemstone’s value is the amount and distribution of flashing rainbow colors, called play-of-color. Play-of-color occurs because of the interaction of light with its internal structure. This causes light waves to diffract, or bend, resulting in spectral colors that range from , red, orange, yellow, green, and blue. There are two broad classes of opal: precious and common. Precious opal displays play-of-color, common opal does not.

“The Path of Enlightenment” necklace contains 180 opals, and is an excellent example of the vast spectrum of colors found in opals. Courtesy of Impressions Ltd.

These gemstones are some times treated to improve their color. Synthetic opal, created in the 1970’s is available in black, white, and fire opal. You may also run across imitation opals made out of glass (called Slocum Stone) and plastic.

If you’re the fortunate owner of a precious opal, the best way to care for it is with warm, soapy water. Ultrasonic cleaning or steam cleaning are never recommended for this fairly delicate gemstone. With a hardness of 5-6.5 on the Mohs scale, it is softer than many gems and should be treated with care.

Opal salamander pin (bottom). (C) GIA and Tino Hammid. Courtesy of Neil Lane, Inc.; Beverly Hills, California.

How would you describe the play-of-color found in opals–flashing rainbow, volcano, galaxy, fireworks? Use your imagination to come up with a way to describe this unique phenomenon.

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Colorful tourmalines. From the Dr. Eduard J. Gubelin Collection.

Historically, tourmalines were often mistaken for other gemstones due to its vast range of colors. One of the “rubies” in the Russian crown jewels, the “Caesar’s Ruby” pendant, is actually rubellite tourmaline. A Spanish conquistador found a green tourmaline crystal in Brazil in the 1500s and confused the gem with an emerald. These types of mistaken identities continued for centuries, until scientists recognized tourmaline as a distinct mineral species in the 1800s.

6.72 carat pink cushion-cut tourmaline and diamond ring. Image courtesy of Omi Prive.

When shopping for this gemstone, color is the most important quality factor to look for. Highly saturated colors without dark areas are the most valuable, but less saturated tones have recently become popular as well. The pink/red variety, known by the trade name rubellite, is one of the most sought-after and readily available tourmaline colors. High-quality tourmalines mined from Paraíba, a famed Brazilian source of the gemstone, command a premium.

Tourmaline, diamond and gold flower brooch. Image courtesy of Christie’s Images / The Bridgeman Art Library.

These gemstones often grows in environments rich in liquids, which can capture inclusions during crystal formation. The most typical inclusions resemble thread-like cavities parallel to the length of the crystal. If cut as a cabochon, these inclusions can appear as a striking a cat’s eye effect.

Cut is also an important factor when selecting a tourmaline. Many gem cutters orient a tourmaline based on its depth of color. They are often cut in long rectangles to accentuate the gemstone’s pleochroism, meaning it shows different colors when viewed from different directions.

While tourmalines can reach extraordinary sizes, fine-quality stones are very rare, so large-sized gems rise considerably in per-carat price. Availability drops and prices rise sharply for facet-quality rough material.

The Hamlin necklace. Courtesy of the Harvard Mineralogical Museum.

Tourmaline is rated 7 to 7.5 in hardness on the Mohs scale and is suitable for everyday wear. These colorful gems are generally stable enough to withstand light and most chemicals, but heat can be damaging. Warm soapy water and a soft toothbrush is the best method for cleaning tourmaline. The use of ultrasonic and steam cleaners is not recommended.

With such a wide variety of colors and color combinations available, which color of tourmaline are you most drawn to?

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Think of every passing year as an opportunity to celebrate with your birthstone. In fact, people have been wearing birthstone jewelry since the 15^th century in Poland, when they were encouraged to own all 12. And while birthstone secrets and lore can be found right here on our blog, today we share what makes YOUR birthstone a powerful statement of your finest qualities.

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