January

People typically think of garnet, January’s birthstone, as being red, and many of them are. But garnet also comes in a wide variety of colors, including orange, yellow, green and rarely, purple or blue. Bright orange garnet is known in the trade as “mandarin” garnet. Tsavorite and grossularite are two types of green garnet that can sometimes rival emerald in color. Learn more.

February

Amethyst, February’s birthstone, is the purple variety of quartz. It was especially beloved by the Romans in antiquity, who thought of purple as a royal color, and it was priced similarly to ruby and emerald until the 19th century, when large deposits were discovered in Brazil. Today, amethyst is a relatively affordable gemstone that comes in high clarity and incredibly large sizes. The finest amethyst color is a rich medium-dark to dark reddish-purple or purple. Learn more.

March

Aquamarine, March’s birthstone, means “seawater” in Latin, perhaps because it ranges in color from greenish blue to a rich, saturated medium blue. Brazil is the most important producer of aquamarine, with Santa Maria being its most famous locale. Aquamarine can come in large sizes with high clarity. It is a variety of beryl and is related to emerald and morganite. Learn more.

April

Diamond, April’s birthstone, is the hardest gem on Earth and one of the most popular gems in the world. Not only did diamonds form under great heat and pressure deep within the earth, they were also brought to the surface by volcanoes. Did you know that diamonds range from 90 million to billions of years old? Each diamond is a time capsule that gives scientist insight into Earth’s geologic history. No wonder diamonds are treasured as symbols of strength and eternity. Learn more.

May

Emerald is the perfect birthstone for spring. To many ancient cultures, its lush green symbolized fertility and rebirth. The first known emerald mines were in Egypt, and emeralds were beloved by many powerful rulers, especially Cleopatra. This gem tends to contain many inclusions and is often oiled or fracture-filled. This means emerald jewelry should never be cleaned in an ultrasonic cleaner, which can remove the oil and even cause damage. Some connoisseurs believe that inclusions give emeralds a lush look. That’s why emerald inclusions sometimes are called ‘jardin’ or ‘garden’ in French. Learn more.

June

Pearl – one of June’s birthstones – is perhaps the best-loved gem of all time. Natural pearls sometimes form when an irritant enters a mollusk. The mollusk secretes layers of an iridescent substance, called nacre, to surround the irritant. These layers break up light in a way that creates pearl’s unique luster and orient. Natural pearls are rare, but today, cultured pearls are farmed in large quantities in many countries around the world. The most popular pearl types include: South Sea, Tahitian, akoya and freshwater. Learn more.

July

Ruby – July’s birthstone – sets the standard for all red gems. Long associated with passion and courage due to its fiery color, it is the gem of lovers, kings and warriors. Burma (Myanmar) is a famous historical source known for producing fine-quality rubies, sometimes called “pigeon’s blood” in the trade, that are a saturated red to slightly purplish red with glowing red fluorescence. Most rubies are heat-treated to improve their color and clarity. Untreated rubies with saturated color and clarity are rare. Learn more.

August

Peridot – one of August’s birthstones – is known for its bright, grass-green to yellowish green color. A relatively affordable gem, it is found in large sizes with high clarity. Peridot is 6.5-7 on the Mohs scale, which means it requires some care when worn. It may show scratches if worn in a ring, but it is well suited for a pendant or earrings. An extreme gem, peridot forms in Earth’s mantle and reaches the surface through volcanoes. Peridot has also been discovered in meteorites and in outer space, including on the moon and on comets. Learn more.

September

Sapphire – September’s birthstone – sets the standard for all blue gemstones and has been beloved by royalty and clergy throughout history as a symbol of nobility and fidelity. The most legendary sapphire locales are Kashmir, Ceylon (Sri Lanka) and Burma (Myanmar), with the most prized color being a violetish blue to pure blue, sometimes called “cornflower blue” in the trade. When used by itself, the term “sapphire” refers to blue stones, but there are also fancy colored sapphires that can be pink, purple, green, yellow, orange and more. Sapphire is one of the hardest gemstones on Earth after diamond and is a beautiful, durable choice for any type of jewelry. Learn more.

October

Opal – one of October’s birthstones – is a phenomenal gem that shows rainbow flashes of color. There are many types of opal, with black and crystal opal being the most valuable and white and jelly opal being more commonly seen. Black opal is treasured because its dark body color shows off its play-of-color the most vividly. As beautiful as they are, opals are more fragile than most gems and require special care. They should not be stored in dry conditions (a safe) or exposed to heat (from a heater, stove, etc.). Otherwise, they may craze (develop a series of cracks). Opals are also relatively soft and should ideally be set in a protective setting if worn as a ring stone. Learn more.

November

Historically, topaz – one of November’s birthstones – was thought to be a golden yellow stone. But modern gemologists know that topaz actually comes in a wide variety of colors, including blue, pink, red, purple and more. Imperial topaz, a trade name for medium reddish orange to orange-red topaz, is among the gem’s most desirable colors. Blue topaz, most of which has been irradiated and heated, is one of the most popular and affordable gems on the market today. Topaz has high hardness and makes for durable jewelry. Learn more.

December

Tanzanite – one of December’s birthstones – is among Earth’s rarest gemstones. This blue to violet or purple gemstone is found only in one place – at the foot of Mount Kilimanjaro in Tanzania. Its color can rival that of the finest sapphire. Tanzanite shows three different colors when viewed in three different crystal directions: red-violet, deep blue, and yellow green. Today, most tanzanite is heat treated, which removes or reduces the yellow green or brownish pleochroic color, maximizing the blue and violet. This gorgeous stone’s main drawback is that it has perfect cleavage, meaning it can break or split if hit in the right (or wrong) direction. That means it is best suited for a pendant or earrings and should probably not be worn as an everyday ring stone. Learn more.