Though peridot is widely recognized by its brilliant lime green glow, the origin of this gemstone’s name is unclear. Most scholars agree that the word “peridot” is derived from the Arabic faridat, which means “gem,” but some believe it’s rooted in the Greek word peridona, meaning “giving plenty.” Perhaps that’s why peridot was, according to lore, associated with prosperity and good fortune.
Peridot is the rare gem-quality variety of the common mineral olivine, which forms deep inside the Earth’s mantle and is brought to the surface by volcanoes. In Hawaii, peridot once symbolized the tears of Pele, the volcano goddess of fire who controls the flow of lava. Rarely, peridot is also found inside meteorites.
Peridot’s signature green color comes from the composition of the mineral itself—rather than from trace impurities, as with many gemstones. That’s why this is one of few gemstones that only comes in one color, though shades may vary from yellowish-green to olive to brownish-green, depending how much iron is present.
Though it is known as “the Evening Emerald” because its sparkling green hue, peridot looks good any time of day.
Most of the world’s peridot supply comes from the San Carlos Reservation in Arizona. Other sources are China, Myanmar, Pakistan, and Africa.
Peridot only measures 6.5 to 7 on the Mohs scale, so while the raw crystal is prone to cracking during cutting, the finished gemstones are robust and easy to wear.
Sardonyx combines alternating layers of sard and onyx—two types of the layered mineral chalcedony—to create a reddish zebra-striped gemstone with white bands.
Its name, similarly, combines sard (referencing the ancient Persian city, Sardis, in present-day Turkey, where the red stone was found) with onyx (from the Greek word of the same spelling, which meant “nail or claw.”)
Sard ranges in color from yellowish red to reddish brown, depending on how much iron oxide is present. Sard is easily confused with carnelian, another type of chalcedony that is slightly softer and lighter in color.
Sardonyx, like onyx, shows layers of parallel bands—instead of the chaotic, curved bands that compose agate, another type of chalcedony.
The finest examples of sardonyx, which display sharp contrasts between layers and are found in India. Other sources include Brazil, Germany, Czech Republic, Slovakia, Madagascar, Uruguay and the United States.
Measuring 6.5 on the Mohs hardness scale, sardonyx is widely available and relatively inexpensive as gems, beads, and jewelry. It is often carved into cameos, intaglios and brooches to show the color contrast between layers.
Used as a stone of strength and protection in ancient times, sardonyx is associated with courage, happiness, and clear communication. Ancients believed that placing a sardonyx gemstone at each corner of a house will grant protection against evil.
The spinel is often mistaken either a ruby or pink sapphire, as it can resemble either. In fact, some of the most famous rubies in history have turned out to be spinel. But its distinguishing features, like its octahedral crystal structure and single refraction, are what sets it apart from other gemstones. Spinel also has a lower Mohs hardness than ruby and sapphire.
Significant deposits of spinel have been found in Cambodia, Myanmar, Sri Lanka, and Thailand. It has also been found in Afghanistan, Australia, Brazil, Madagascar, Nepal, Nigeria, Tadzhikistan, Tanzania and the U.S.
Vivid red is the most desirable color of spinel gemstones, followed by cobalt blue, bright pink and bright orange. The more affordable gemstones are often those with paler colors, like lavender. You may also find spinel in black, violet blue, greenish blue, grayish, pale pink, mauve, yellow or brown.
When shopping for spinel, a high-quality gemstone should have no visible inclusions. The more inclusions, the less valuable the gemstone. Spinel birthstones can be found in various cuts such as octagons, trillions, squares, rounds, ovals, pears, and cushions.