Peridot, spinel and sardonyx are the three birthstones for August. The peridot birthstone is known for being formed under extreme conditions, as it can be found in the hardened lava that carried it from deep within Earth’s mantle as well as in meteorites that travelled from outer space.
The spinel birthstone was underappreciated until recently, as today’s consumers look for an alternative to ruby, a gem with which red spinel was mistaken for centuries. Sardonyx is the original August birthstone.
Peridot is the yellowish green to greenish yellow gem variety of the mineral olivine. Throughout history, peridot has often been confused with other gems such as topaz and emerald. The Red Sea island of Topazios, a purported source of the name “topaz,” actually produced peridot.
The word “peridot” comes from the Arabic faridat, meaning gem. This August birthstone was valued in many ancient and medieval cultures.
With a hardness of 6.5 to 7 on the Mohs scale of harness, peridot is softer than many gems and cannot take hard wear, so it is not recommended for daily use in a ring. This August birthstone can also be damaged by some acids and even by long-term exposure to acidic perspiration. Cleaning peridot is a delicate process. Never use a steam or ultrasonic cleaner, as your peridot birthstone is vulnerable to thermal shock. It is safest to use an s0ft-bristle brush with a mild dish soap in warm water. Peridot should be stored with care to avoid scratching by gems with greater hardness.
The name “spinel” comes from the Latin word spina, which means thorn, in reference to the shape of spinel crystals. This second August birthstone comes in a wealth of colors: intense red, vibrant pink, orange, purple, violet, blue and bluish green.
Spinel is 8 on the Mohs scale of hardness, so it is typically a durable gem for rings and other jewelry. Ultrasonic and steam cleaners can be used; however, the presence of fractures could pose a problem. Warm soapy water is always a safe alternative.
Spinel is stable when exposed to light and chemicals. High heat can cause some colors of this August birthstone to fade.
Sardonyx is believed to be one of the stones in the High Priest’s breastplate, as referred to in the Old Testament, and to represent the strength of spiritual life. Roman soldiers wore sardonyx rings with the image of Mars carved on them for protection in battle. Today, this August birthstone is associated with courage, happiness and clear communication, bringing stability to marriage and partnerships.
This August birthstone is 6.5 to 7 on the Mohs scale. As with peridot, care should be taken when wearing it, especially as a ring. Note that sardonyx, like other forms of chalcedony, is commonly dyed. High heat, as in jewelry manufacturing or repair techniques, might affect the color of dyed sardonyx.