August 19, 2019

If your birthday is in August, you have two birthstones—the gems associated with the month of your birth: peridot and sardonyx. Peridots are a variety of a common rock-forming mineral called olivine. A high iron content gives peridots their distinctive green color. The sardonyx is a multi-colored variety of chalcedony, a fine-grained form of the mineral quartz. Most sardonyx has straight or slightly curved bands of reddish-brown and white. Both peridot and sardonyx have long been used in jewelry and decorative objects.

Peridot is one of two August birthstones. The other is sardonyx. Credit: © Albert Russ, Shutterstock

Peridots have been known since Biblical times, and legend says the stones improve health, guard against insanity, and slow the human aging process. Peridots are also said to increase assertiveness, patience, and clarity of thought and to encourage prosperity and happiness. Jewelers cut and polish the highest-quality peridot stones so that each gem has many flat surfaces called facets. Faceted peridots are used in all types of fine jewelry. Jewelers cut lesser-quality peridots into a rounded style called cabochon or polish them with abrasives in a process called tumbling. These lesser-quality peridots are used in costume jewelry and decorative objects. The earliest source of peridots was Jazirat Zabarjad (St. John’s Island), off the Egyptian coast in the Red Sea. In the United States, Arizona and New Mexico are important commercial sources of peridots.

Sardonyx is a multi-colored variety of chalcedony. Credit: © Vlad3563/Dreamstime

In ancient Egypt, sardonyx was considered a protective stone, and it was used to ward off evil. Modern folklore credits sardonyx with encouraging confidence, creativity, happiness, integrity, optimism, and even virtuous behavior. It is said to help students preparing for exams, authors dealing with writers block, or anyone faced with a job requiring mental discipline. Jewelers usually cut sardonyx flat or with a domed shape to bring out the bands of color. Cameos (engraved gems) are sometimes cut from sardonyx to take advantage of its color. The chief sources of sardonyx are Brazil, India, and Uruguay.

Click to view larger image
Birthstones, according to tradition, bring good luck when worn by a person born in the associated month. Credit: WORLD BOOK illustrations by Paul D. Turnbaugh

According to tradition, a birthstone brings good luck to a person born in its month. Each birthstone also corresponds to a sign of the zodiac. The belief in birthstones may have come from a Bible story about Aaron, the first high priest of the Israelites. The story describes Aaron’s breastplate, which was decorated with 12 precious stones. Early writers linked these stones with the 12 months of the year and the 12 signs of the zodiac. The custom of wearing a stone that represented a person’s zodiac sign probably originated in Germany or Poland in the 1700′s.

March 11, 2019

If your birthday is in March, you have two birthstones (gems associated with the month of your birth): aquamarine and bloodstone (a variety of chalcedony). Aquamarine is a light blue or bluish-green gem. It is cut in facets (polished flat surfaces) and used in all types of jewelry. Bloodstone is a dark green gem with red spots. It too is used in jewelry, but it is also associated with Christianity.

Aquamarine is one of two birthstones for the month of March. Credit: © Albert Russ, Shutterstock

Aquamarine is a variety of the mineral beryl. The most popular color is a clear sky-blue. Aquamarine is often treated with heat to improve its color. Almost all aquamarine is transparent. Aquamarines have been known since ancient times, when legends said the gems could help people relax or could act as an antidote to poison. The ancient Romans believed the gem could cure laziness and produce courage. The most important source of aquamarines is Brazil.

Bloodstone is another birthstone of March.
Credit: © Shutterstock

Bloodstone, a variety of the mineral Chalcedony, is related to agate, carnelian, and onyx. Chalcedony was named for the ancient town of Chalcedon, in what is now Turkey, which is near deposits of the mineral. Bloodstone is sometimes called Martyr’s Stone or Christ’s Stone because legend attributed the gem’s red spots to the blood of Jesus Christ. The ancient Greeks called bloodstone heliotrope (also a type of flower) for the way it reflects light. The Babylonians used bloodstone to make amulets, decorative vessels, and seals.

Click to view larger image
Birthstones, according to tradition, bring good luck when worn by a person born in the associated month. Credit: WORLD BOOK illustrations by Paul D. Turnbaugh

According to tradition, a birthstone brings good luck to a person born in its month. Each birthstone also corresponds to a sign of the zodiac. The belief in birthstones may have come from a Bible story about Aaron, the first high priest of the Israelites. The story describes Aaron’s breastplate, which was decorated with 12 precious stones. Early writers linked these stones with the 12 months of the year and the 12 signs of the zodiac. The custom of wearing a stone that represented a person’s zodiac sign probably originated in Germany or Poland in the 1700′s.