The history of ornamental gemstones dates back to ancient civilizations, including the Egyptians and Greeks, who believed these stones had metaphysical properties. These civilizations also assigned these gemstones to zodiac signs according to their properties. In the 20th century, the U.S.-based National Association of Jewelers, or NAJ, assigned gemstones to the 12 months. The NAJ loosely based its assignments on the original zodiac charter.
December has three birthstones. Two of the birthstones, blue topaz and turquoise, have bluish colors. Tanzanite, the third birthstone, has a purplish color. Turquoise has been used commercially for more than 5,000 years, making it the oldest of the three.
The birthstone for January is garnet. Almondine are the most common garnets and these stones possess dark red and orangish-red colors. The term “garnet” derives from the Latin term “granatum malum” or “pomegranate,” a reddish fruit.
Amethyst is the February birthstone. This birthstone is a mineral quartz and features a purplish color. In the zodiac, amethysts are the stones for the Pisces sign. The term “amethyst” comes from the Greek language, translating to “not drunken.”
March's birthstone is aquamarine, a light blue gemstone. The origins of aquamarine date back to the ancient Greeks in the fifth century B.C. In ancient times, sailors and seamen believed wearing an aquamarine would prevent them from being harmed at sea.
Diamonds are the birthstones of April. Most diamonds have a slight yellow tint, but the rarest diamonds are colorless. The tradition of using diamonds as wedding engagement rings dates back to the 15th century when Archduke Maximilian of Austria gave his fiancee a diamond ring.
People born in May have an emerald as their birthstone. An emerald has a dark green color. The mining of emeralds dates back to ancient Egypt. In ancient Egyptian culture, emeralds were buried with the dead, believing it would grant the deceased eternal youth.
The birthstone for June is a pearl. Pearls possess a wide array of colors, including pink, black and white. These birthstones form in the soft tissue of a mollusk. Cultured pearls are natural pearls formed by human intervention, while natural pearls occur without the help of humans.
For July, the birthstone is a ruby. This precious gemstone is red. Rubies are mined in Southeast Asia and eastern Africa. The origin of “ruby” comes from the Latin word “ruber,” which translates into “red."
Peridots are the birthstones of August. These semiprecious gemstones have a yellowish-green color. The peridot has been closely tied to religion and spirituality since ancient times, when Egyptian priests used the stone in their rituals.
The first birthstone of the autumn season is sapphire, September's birthstone. This precious gemstone primarily comes in dark blue; however, alternate colors for sapphires include violet and gray. Sapphires originated from the island of Sappherine in the Arabic Sea more than 2,000 years ago.
Opal, the October birthstone, comes in a variety of colors. The primary colors for opal are black, red, golden and milky white. This semiprecious gemstone is the national gemstone for Australia and is often presented as a gift for 14th- and 18th-year wedding anniversaries.
The November birthstone is citrine, a dark yellowish semiprecious gem. The term “citrine” comes from the French word “citrin,” which means “lemon” in English. Citrine's history dates back to the ancient Roman era and became popular in the era of 18th-century Romanticism.