June is one of only two months that has three birthstones associated with it, giving the lucky people born in June a choice of gemstones between pearl, alexandrite, and moonstone.
June’s birthstones range from creamy-colored opalescent pearl and moonstone to the rare color-changing alexandrite. With this spectrum of price points and color options, people with June birthdays can choose a beautiful gemstone to fit any mood or budget.
Pearls are the only gemstones made by living creatures. Mollusks produce pearls by depositing layers of calcium carbonate around microscopic irritants that get lodged in their shells, usually not a grain of sand as commonly believed.
While any shelled mollusk can technically make a pearl, only two groups of bivalve mollusks (or clams) use mother-of-pearl to create the iridescent “nacreous” pearls that are valued in jewelry. These rare gemstones don’t require any polishing to reveal their natural luster.
Appropriately, the name “pearl” comes from the Old French perle, from the Latin perna meaning “leg,” referencing the leg-of-mutton shape of an open mollusk shell. Because perfectly round, smooth natural pearls are so uncommon, the word “pearl” can refer to anything rare and valuable.
The rarest and most expensive pearls are natural pearls made in the wild, without human interference. The majority of pearls sold today are cultured or farmed by implanting a grafted piece of shell (and sometimes a round bead) into pearl oysters or freshwater pearl mussels.
Pearls are very soft, ranging between 2.5 and 4.5 on the Mohs scale. They are sensitive to extreme heat and acidity; in fact, calcium carbonate is so susceptible to acid that authentic pearls will dissolve in vinegar.
The finest pearls have a naturally reflective luster, making them appear creamy white with an iridescent sheen that casts many colorful hues.
Cultured freshwater pearls can also be dyed yellow, green, blue, brown, pink, purple or black.
Black pearls, which are mostly cultured because they are so rare in nature—aren’t actually black but rather green, purple, blue or silver.
Pearls used to be found in many parts of the world, but natural pearling is now confined to the Persian Gulf waters near Bahrain. Australia owns one of the world’s last remaining pearl diving fleets and still harvests natural pearls from the Indian Ocean.
Today, most freshwater cultured pearls come from China. South Sea pearls are cultured along the northwestern coastline of Australia, the Philippines, and Indonesia.
A relatively modern gemstone, alexandrite was discovered in Russian emerald mines located in the Ural Mountains. Legends claim that it was discovered in 1834 on the same day that future Russian Czar Alexander II came of age, and was named to honor him.
Often described as “emerald by day, ruby by night,” alexandrite is a rare variety of the mineral chrysoberyl that changes color from bluish green in daylight to purplish red under incandescent light.
This chameleon-like color shift is the result of its uncommon chemical composition which includes traces of chromium, the same coloring agent found in emerald. The unlikelihood of these elements combining under the right conditions makes alexandrite one of the rarest and most expensive gemstones on earth.
The alexandrite mined from Russia’s famed deposits set the quality standard for this gemstone. Today most alexandrite comes from Sri Lanka, Brazil, and East Africa generally paling in comparison to the vivid colors of Russian gemstones.
With a hardness of 8.5 on the Mohs scale, alexandrite is softer than sapphire and harder than garnet—the other gemstones that can change color. However, due to its scarcity, alexandrite is more valuable than most gemstones, even rubies and diamonds.
Associated with concentration and learning, alexandrite is believed to strengthen intuition, aid creativity and inspire imagination, bringing good omens to anyone who wears it.
June’s third birthstone, moonstone, was named by the Roman natural historian Pliny, who wrote that moonstone’s shimmery appearance shifted with the phases of the moon.
The most common moonstone comes from the mineral adularia, named for an early mining site near Mt. Adular in Switzerland that supplied this gemstone. This site also birthed the term adularescence, which refers to the stone’s milky glow, like moonlight floating on water.
Moonstone is composed of microscopic layers of feldspar that scatter light to cause this billowy effect of adularescence. Thinner layers produce a bluish sheen and thicker layers look white. Moonstone gems come in a range of colors spanning yellow, gray, green, blue, peach and pink, sometimes displaying a star or cat’s eye.
The finest classical moonstones, colorlessly transparent with a blue shimmer, come from Sri Lanka. Since these sources of high-quality blue moonstones have essentially been mined out, prices have risen sharply.
Moonstones are also found in India, Australia, Myanmar, Madagascar and the United States. Indian gemstones which are brown, green or orange in color are more abundant and affordably priced than their classical blue counterparts.
This beautiful gemstone’s weakness is its relatively low hardness of 6 on the Mohs scale, making it prone to stress cracking and cleaving. Care is required with moonstone jewelry like rings or bracelets; so sometimes brooches and pendants are preferred for long term durability.