June's Birthstones - Pearl, Moonstone & Alexandrite

Posted on June 01, 2017 by Tammy Williams

June counts three gems as birthstones – Pearl, Moonstone, and Alexandrite. People born under the Gemini sign are privileged to have such a range of gemstones to choose from and should be able to find one that suits their own personal style. The pearl is also the 3rd and the 30th anniversary gemstone, while the Alexandrite is the 55th anniversary gemstone.

Pearl

The birthstone most commonly associated with June is the Pearl.  Unlike most gemstones that are found within the Earth, pearls have an organic origin. They are created inside the shells of certain species of oysters and clams. Pearls are made mostly of aragonite, a relatively soft (2.5 to 4.5 on Moh’s scale of hardness) carbonate mineral (CaCO3) that also makes up the shells of mollusks. Care should be taken with all pearls as they can be easily damaged. Since they are mostly calcium carbonate they are susceptible to weak acids and can be dissolved with vinegar even.  Pearls come in a wide array of colors, with white or cream being the most common. Some pearls are found naturally in mollusks that inhabit the sea or freshwater settings such as rivers. However, many pearls today are cultured, raised in oyster farms that sustain a thriving pearl industry. 

A pearl is created when a very small fragment of rock, a sand grain, or a parasite enters the mollusk’s shell. It irritates the oyster or clam, who responds by coating the foreign material with layer upon layer of nacre, the iridescent shell material. Pearls formed on the inside of the shell are usually irregular in shape and have little commercial value. However, those formed within the tissue of the mollusk are either spherical or pear-shaped, and are highly sought out for jewelry. Fine quality natural pearls are very rare and as such are highly prized and can be pricey. A good alternative to natural pearls are cultured pearls. Cultured pearls are created the same way as natural pearls except that the foreign substance (usually a bead or a piece of tissue) is deliberately placed in the mollusk. This process typically takes between 2 and 7 years to produce a pearl.  The only way to tell a cultured from a natural pearl is through x-ray to reveal its internal structure.  There are also quite a few fake/imitation pearls in the market that are simply made of mother of pearl or conch shell, or even of glass that is coated with an iridescent solution containing fish scales. Imitation pearls do initially look the part, but they do not have the same weight or smoothness, and their luster will dim greatly too.  It is fairly easy, at least most of the time, to tell fake from natural or cultured pearls by simply rubbing the pearl against your teeth or against each other. A fake pearl will be smooth, and real pearls will feel somewhat rough or gritty.

Pearls possess a uniquely delicate translucence and luster that place them among the most highly valued of gemstones. The color of the pearl depends very much on the species of mollusk that produced it, and its environment. White is perhaps the best-known and most common color. However, pearls also come in delicate shades of black, cream, gray, blue, yellow, lavender, green, and mauve. Tahitian pearls (also called black pearls but are very rarely black), are found in the waters around the French Polynesian islands. Black pearls can also be found in the Gulf of Mexico and can be identified from the Tahitian pearls since they fluoresce somewhat red under ultraviolet light. The Persian Gulf and Sri Lanka are well-known for exquisite cream-colored pearls called Orientals. Other localities for natural seawater pearls include the waters off the Celebes in Indonesia, the Gulf of California, and the Pacific coast of Mexico. The Mississippi River and forest streams of Bavaria, Germany, contain pearl-producing freshwater mussels. Japan is famous for its cultured pearls. Cultured pearl industries are also carried out in Australia and equatorial islands of the Pacific. Some of the tradenames used for the cultured pearls are the Akoya (named for a variety of mollusk used), black Tahitian, and white or golden South Sea pearls. A controversial pearl, the Keshi (sometimes incorrectly spelled Keishi) pearl, is actually considered a bi-product of cultured pearl farming and is a “pearl” created without a nucleus. The controversy is based on arguments between scientists about whether these are natural or cultured. These pearls are never round, but have a beautiful luster as they are made of up of many layers of the iridescent nacre material. They can be any color of the mollusk shell material.

The largest pearl in the world is believed to be about three inches long and two inches across, weighing one-third of a pound. Called the Pearl of Asia, it was a gift from Shah Jahan of India to his favorite wife, Mumtaz, for whom he also built the Taj Mahal.

La Peregrina (the Wanderer) is considered by many experts to be the most beautiful pearl. It was said to be originally found by a slave in Panama in the 1500s, who gave it up in return for his freedom. In 1570, the conquistador ruler of the area sent the pearl to King Philip II of Spain. This pear-shaped white pearl, one and a half inches in length (50-56 carats), hangs from a platinum mount studded with diamonds. The pearl was passed to Mary I of England, then to Prince Louis Napoleon of France. He sold it to the British Marquis of Abercorn, whose family kept the pearl until 1969, when they offered it for sale at Sotheby’s. Actor Richard Burton bought it for his wife, Elizabeth Taylor. In 2011 it sold for $11.8 million.

Matched natural pearls are very rare, the Baroda Pearls, once part of the Maharaja of Baroda’s necklace are a double strand of 68 pearls that sold for $7 million in 2007.

Pearls, according to South Asian mythology, were dewdrops from heaven that fell into the sea. They were caught by shellfish under the first rays of the rising sun, during a period of full moon. In India, warriors encrusted their swords with pearls to symbolize the tears and sorrow that a sword brings. Pearls were also widely used as medicine in Europe until the 17th century. Arabs and Persians believed it was a cure for various kinds of diseases, including insanity. Pearls have also been used as medicine as early as 2000 BC in China, where they were believed to represent wealth, power and longevity. Even to this day, lowest-grade pearls are ground for use as medicine in Asia. It is no wonder that they are considered to represent health and longevity, since the pearl is created by creating layer upon layer of nacre covering the threat of the foreign body to the mollusk.

Pearls are truly fascinating, but unless you want a book about them I better stop here !

Moonstone
Moonstone is another of June’s birthstones. Moonstones are believed to be named for the visual effect or sheen, that when held up to light project an enchanting silvery play of color /light very much like moonlight. It truly is a wondrous and mysterious stone, when the stone is moved back and forth, the brilliant rays appear to move about, much like moonbeams playing over water. It happens to be one of my favorite stones to just site and play with in the light as no two seem to be exactly alike.

This gemstone belongs to the family of minerals called feldspars, an important group of silicate minerals commonly formed in rocks. About half the Earth’s crust is composed of feldspar. This mineral occurs in many igneous and metamorphic rocks, and also constitutes a large percentage of soils and marine clays.

Rare geologic conditions produce gem varieties of feldspar such as moonstone, labradorite, amazonite, and sunstone. They appear as large clean mineral grains, found in pegmatites (coarse-grained igneous rock) and ancient deep crustal rocks. Feldspars of gem quality are aluminosilicates (minerals containing aluminum, silicon and oxygen), that are mixed with sodium and potassium. The stones are relatively hard at 6.0 on Mohs scale of hardness.  The best moonstones are from Sri Lanka. They are also found in the Alps, Madagascar, Myanmar (Burma), and India. The Sri Lanka moonstones shimmer a pale blue and are almost transparent, while the ones found in India have a more nebulous play of light and shadow on backgrounds of beige, brown, or even green or orange.

The ancient Roman natural historian, Pliny, said that the moonstone changed in appearance with the phases of the moon, a belief that persisted until the sixteenth century. The Romans and the Greeks associated this stone with lunar deities.  The ancient Romans believed that the image of Diana, goddess of the moon, was enclosed within the stone. Moonstones were believed to have the power to bring victory, health, and wisdom to those who wore it. It is also known as the Travelers Stone for the protection it gives the wearer, especially at night. As such, these were also thought to give protection for those while on shamanistic journeys.

In India, the moonstone is considered a sacred stone and often displayed on a yellow cloth – yellow being considered a sacred color. The stone is believed to bring good fortune, brought on by a spirit that lives within the stone and is a traditional wedding gift.

In more recent history the stone became popular during the Art Nouveau period. The moonstone was used in an inordinately large number of pieces crafted by the famous goldsmith Rene Lalique.

Alexandrite
June’s third birthstone is the alexandrite, as well as it being the stone for 55th anniversaries. Alexandrite is a highly sought after variety of Chrysoberyl that possesses an enchanting chameleon-like coloring. In daylight, it appears as a beautiful green, sometimes with a bluish cast or a brownish tint. However, under artificial lighting, the stone turns reddish-violet or violet. The duality of this stone matches those born under the Gemini sign perfectly.

As mentioned, the Alexandrite belongs to the Chrysoberyl family, a mineral called beryllium aluminum oxide in chemistry jargon that contains the elements beryllium, aluminum and oxygen. It is a relatively hard mineral (about 8.5 out of 10 on Moh’s hardness scale), only surpassed in hardness by diamonds and corundum (sapphires and rubies). The unusual colors in alexandrite are attributed to the presence of slight impurities of the metal chromium. Chrysoberyl is found to crystallize in pegmatites (very coarse-grained igneous rock, crystallized from magma) rich in beryllium. They are also found in alluvial deposits – weathered pegmatites, containing the gemstones, which are carried by rivers and streams.

Alexandrite is an uncommon stone, and therefore very expensive.  They were first discovered in the Ural Mountains of Russia, but the Russian deposits have long been exhausted and it is very rare to find any from Russia.  Sri Lanka is the main source of alexandrite today, and the stones have also been found in Brazil, Madagascar, Zimbabwe, Tanzania, and Myanmar (Burma). Synthetic alexandrite, resembling a reddish-hued amethyst with a tinge of green, has been manufactured but the color change seen from natural to artificial lighting cannot be reproduced. However, laboratory grown Alexandrite does exhibit color changes with a wide variety of green to purple and blue to purple color-changes. Natural Alexandrite is so rare and expensive they have likely been seen by very few people.  These lab-grown specimens make them very affordable though.

The stone is named after Prince Alexander of Russia, who was to become Czar Alexander II in 1855. Discovered in 1839, rumored to be on the prince’s birthday, Alexandrite was found in an emerald mine in the Ural Mountains of Russia. The story is that while mining an Emerald mine, the miners brought the stones out in the sunlight and found one that was red. But in the morning when they awoke it was green again, so they realized they had a new type of gemstone on their hands.  It became very popular then and was soon played out in Russia. America’s Tiffany Company did much to popularize the gemstone, when Tiffany’s master gem buyer George Kunz fell in love with the stone.  

Because it is a relatively recent discovery in the 19th century, there has not been much time for it develop the typical myths and superstitions surrounding this gemstone. In Russia, the stone was also popular because it reflected the Russian national colors, green and red, and was believed to be a good omen.

 

Sources:

EarthSky. http://earthsky.org

American Gem Society: https://www.americangemsociety.org/en/june-birthstones

Wikipedia. https://en.wikipedia.org/wiki/Moonstone_(gemstone)

http://www.minerals.net/gemstone/alexandrite_gemstone.aspx

 

 

 

Posted in Alexandrite, June, Moonstone, Pearl


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