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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Ready for a stunning surprise? Put a gemstone under a high-powered microscope, and you’ll see a world of breathtaking beauty.

GIA researchers explore this hidden universe by photographing gemstones at magnifications up to 1,000 times larger than what the unaided eye can see. Called photomicrography, this technique is used to capture the internal gemological characteristics that are revealed under the microscope. These characteristics can help gemologists determine if a gemstone is natural, synthetic, or treated.

The night sky lit up by shooting stars?

Photomicrography has another benefit. Gemstones are geologic time capsules, and by documenting their inclusions (microscopic characteristics enclosed within a gem), researchers can study the environment in which it grew. Sometimes scientists can use this information to help them provide an opinion  from where a gem originated. That’s important information because in some cases the same species of gemstone can sell for dramatically different prices depending on the country from which it was mined.

GIA researchers continue to use photomicrography to advance the science of gemology. The images in this blog are just a sampling of some of the stunning beauty that is revealed…modern art or microscopic science?

Trigons on Diamond. Magnification 200x

On this rough diamond from Wyoming, trigons, which are triangular indented growth marks on the surface, appear as colliding tectonic plates pushing pyramidal shapes into the sky – or so it seems to the imagination.

Apatite with Hematite Discs. Magnification 200x

Life begins as a cell divides is our imaginative interpretation of hematite discs in apatite from Mexico

Negative Crystal in Quartz. Magnification 50x.

A blue crystal that appears to be floating.  This is the illusion made by this petroleum-filled negative crystal in quartz from Pakistan. A negative crystal is an angular void within a gem that is sometimes filled with a liquid, solid, gas or combination of these three phases.

Fire agate. Magnification 25x

Imagine the canyons of New Mexico at sunset, but instead of being painted in desert hues it shimmers in a rainbow of colors. This fire agate seems well suited for our fanciful scene.

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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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A gemstone that conjures up images of heaven and earth, life and death, yin and yang, jade remains hugely popular in China, and all across the world. But did you know that jadeite is available in lavender (but not in pink?)

Find out these obscure facts and more with our exclusive Jade Buying Guide, which we’ve created as an infographic for our readers’ convenience. It’s packed with practical tips and quality factors to consider during the buying process, as well as answers to a few commonly asked questions we’ve heard bandied about over the years.

The guide is quick to download, easy to print, and makes for a handy visual companion to share with all your fellow jade enthusiasts. 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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Judging by what celebrities wear on the red carpet, luxury cocktail rings continue to reign supreme. If you’re looking to bring some sparkle to your favorite Valentine, consider giving her (or him?) a ring with gems of grand proportions, one that’s a fashion statement and a work of art. But be warned: while these jumbo rings dazzle on the red carpet, only some may be suitable for everyday wear.

One factor in determining a gem’s durability is its hardness or resistance to scratching. (There are other durability factors like toughness or resistance to breaking; and stability –  how a gem reacts to the effects of heat, light or chemicals. We’ll cover these in future posts.) Gemologists use the Mohs scale to describe the relative hardness of a stone. The scale runs from 1 to 10 and the higher the number, the harder the mineral.

We spotted some spectacular cocktail rings on the fingers of celebs at last fall’s Emmy Awards, and couldn’t resist rating them on the Mohs scale.

Diamonds rank a perfect 10 on the Mohs scale, and appeared on Emmy-winner Claire Danes from Showtime’s Homeland. She sparkled with a Neil Lane five carat elongated emerald-cut flawless diamond ring. Zosia Mamet from the HBO series Girls chose a black and brown diamond globe ring by Demarco. Uniquely strong,diamonds are the perfect accessory from the carpool to the catwalk.

Five carat elongated emerald-cut flawless diamond ring. Courtesy Neil Lane.

Beautiful and elegant black and brown diamond globe ring. Courtesy of Demarco.

Both Neil Lane ruby rings on The Big Bang Theory’s Kaley Cuoco rate a 9. Their vibrant red color is highly prized and in demand. Provided they are not heavily included, these romantic gems are quite durable for wearing daily.

Vibrant red rubies are highly prized and in demand. Courtesy of Neil Lane.

A pink topaz ring by Fred Leighton gleaming on Girls actress Allison Wiliams receives an 8.

Emeralds, like this 40 carat Lorraine Schwartz showstopper worn by Modern Family’s Sofia Vergara, rank between 7.5 and 8. Rings set with emeralds or topaz are perfect for a special occasion or a formal event. Care should be taken because they can chip, and high heat or chemicals could cause damage.

40 carat emerald Lorraine Schwartz ring worn by Modern Family’s Sofia Vergara.

Jorge Adeler “Rock Candy” ring with Citrine.

New Girl star Zooey Deschanel impressed with an ice blue tourmaline cocktail ring by Chanel. Its dazzling color range unmatched, tourmaline’s hardness is rated 7 to 7.5. Right alongside with a hardness of 7 is the citrine, worn by Taylor Schilling from the new Netflix series Orange is the New Black. Her “Rock Candy” ring by Jorge Adeler glistened a warm yellow. Both tourmaline and citrine could be damaged by chemicals, or prolonged exposure to sun or heat.

Zooey Deschanel wearning with an ice blue tourmaline cocktail ring by Chanel.

It’s best to consult a credentialed jeweler on the proper care for your valuable gems, however most stones can withstand mild cleaning with warm, soapy water. Learn more information on the Mohs scale and how other gems rank before your next purchase.

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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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