by Ann Covode
The birthstones chosen for August are peridots and spinels. Both have an interesting history and are beautiful!
Peridot is one of the few gemstones that occur in only one color: an olive-green. The intensity and tint of the green, however, depends on the percentage of iron in the crystal structure, so the color of individual peridot gems can vary from yellow, to olive, to brownish-green. In rare cases, peridot may have a medium-dark toned, pure green with no secondary yellow hue or brown mask. Olivine, of which peridot is a type, is a common mineral in mafic and ultramafic rocks, often found in lava and in peridotite xenoliths of the mantle, which lava carries to the surface; however, gem-quality peridot occurs in only a fraction of these settings.
Peridots can also be found in meteorites. Peridots can be differentiated by size and composition. A peridot formed as a result of volcanic activity tends to contain higher concentrations of lithium, nickel and zinc than those found in meteorites. Olivine is an abundant mineral, but gem-quality peridot is rather rare due to its chemical instability on Earth’s surface. Olivine is usually found as small grains and tends to exist in a heavily weathered state, unsuitable for decorative use. Large crystals of forsterite, the variety most often used to cut peridot gems, are rare; as a result olivine is considered to be precious. In the ancient world, mining of peridot, called topazios then, on St. John’s Island in the Red Sea began about 300 B.C. Peridot is sometimes mistaken for emeralds and other green gems.
Notable gemologist George Frederick Kunz discussed the confusion between emeralds and peridots in many church treasures, notably the “Three Magi” treasure in the Dom of Cologne, Germany. The August birthstone, peridot, symbolizes strength and is sometimes called the “evening emerald” for its light green color.
Eve had fun with both spinels and sapphires in these drop earrings in 18 karat white gold from Eve’s “Just Desserts” series. These lovely “Lime Jello” earrings feature four sapphires, two peridots and four diamonds. $2870
Eve’s “Paradiso” necklace features peridot in multiple bead sizes to create this interesting combination. $390.
Spinel is a gemstone mineral that has been confused with ruby and sapphire for over 1000 years. Several of the most spectacular spinels ever discovered have been mounted in “crown jewels” and other “jewelry of significance” under the assumption that they were rubies or sapphires. Spinel occurs in the same bright red and blue colors as rubies and sapphires. Spinel forms in the same rock units, under the same geological conditions and is found in the same gravels. It is not surprising that ancient gem traders thought that these colorful spinels were rubies and sapphires. Two thousand years ago, gemstone traders did not know that spinel and corundum (the mineral of ruby and sapphire) have different chemical compositions and different crystal structures. Instead, gem traders thought that every bright red gemstone was a “ruby” and every deep blue gemstone was a “sapphire.” As a result, lots of spinels are now in very important jewelry collections based on their incorrect identification as a ruby.
The most famous example of a spinel being identified as a ruby is a 170-carat bright red spinel named “The Black Prince’s Ruby.” The first known owner of this beautiful stone was Abu Sa’id, the Moorish Prince of Granada, in the 14th century. The stone passed through several owners and eventually made its way into the Imperial State Crown of the United Kingdom, where it is mounted immediately above the famous Cullinan II diamond.
In July 2016, spinel was named a new birthstone for the month of August by the American Gem Trade Association and the Jewelers of America. Before then, peridot served as the August birthstone. Now both spinel and peridot will share the designation. This event and continued promotion of monthly birthstones will bring significant attention to spinel, which occurs in a variety of colors. Consumers will now have a choice beyond the yellow-green color of peridot.
Eve’s Bachanal Ring is a glorious example of spinel. This ring in 18 karat white gold from Eve’s “In Great Spirits” series features on Plum Spinel, two raspberry spinels and four pomegranate spinels along with 30 diamonds. This celebratory ring is a one of a kind masterpiece! $14,800
One of our favorites at the Gallery are our Wine Angel necklaces in black Spinel. This elegant necklace measures 60 inches long and can be worn in various lengths as a necklace or bracelet. $210. Also featured here a delicate look with peridot and Freshwater pearls, Eve created this baby bracelet. $48