June birthstones range from the iridescent pearl to the milky moonstone and the rare, color-changing alexandrite. With this range of prices and color options, people with a June birthday can choose a beautiful gemstone to suit any mood or budget.
Pearl
Pearls are the only gemstones made from living creatures. Molluscs produce pearls by depositing layers of calcium carbonate around tiny irritant vectors - usually sand grains, it is widely believed - that settle into their shells.
While any mollusk with a shell can technically make a pearl, only two groups of bivalve molluscs (or mussels) use mother-of-pearl to create the iridescent pearls prized in jewellery. These rare gems require no processing to reveal their natural luster.
The name “pearl” comes from the Old French perle. Also from the Latin perna meaning “strand”, referring to the shape of an open mollusk shell. Because perfectly round, smooth, natural pearls are so rare, the word “pearl” can refer to anything rare and precious.
The rarest and most expensive pearls are natural pearls. Those that have been made in nature without human intervention. The majority of pearls sold today are cultured or bred by implanting an inoculated piece of shell (and sometimes a round bead) into freshwater pearl oysters or pearl oysters or pearl oysters.
Pearls are very soft and range between 2.5 and 4.5 on the Mohs scale. They are sensitive to extreme heat and acidity. In fact, calcium carbonate is so sensitive to acids that genuine pearls dissolve in vinegar.
The best pearls have a natural reflective luster. This makes them appear off-white with an iridescent sheen that gives them many color shades. Cultured freshwater pearls can also be dyed yellow, green, blue, brown, pink, purple or black.
Black pearls are cultivated mostly because they are so rare in nature. They are not actually black but rather green, purple, blue or silver.
Pearls used to be found in many parts of the world. But natural pearl production is now limited to the waters of the Persian Gulf near Bahrain. Australia has one of the last remaining pearl fishing fleets in the world. It still collects natural pearls from the Indian Ocean.
Today, most cultivated freshwater pearls come from China. South Sea pearls are cultivated along the northwest coastline of Australia, the Philippines and Indonesia.
Alexandrite
A relatively modern gemstone, alexandrite was discovered in the Russian emerald mines located in the Ural Mountains. Legends claim that it was discovered in 1834. In fact, on the same day that the future Russian Tsar Alexander II came of age; it was named in his honour.
It is often described as “emerald by day, ruby by night”. Alexandrite is a rare variety of the color-changing mineral chrysoberyl. From bluish-green in daylight to crimson red under glowing light.
This chameleon-like colour change is the result of its unusual chemical composition. It contains traces of chromium, the same pigment found in emerald. The lack of possibility of combining these elements under the right conditions makes alexandrite one of the rarest and most expensive gemstones on Earth.
Alexandrite mined from Russia's renowned deposits sets the quality standard for this gemstone. Today, the majority of Alexandrite comes from Sri Lanka, Brazil and East Africa. It generally pales 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 colour. However, because of its rarity, alexandrite is more valuable than most gemstones. Including rubies and diamonds.
Moonstone
June's third birthstone, the moonstone, is named after the Roman natural historian Pliny. He wrote that the moonstone's brilliant appearance changes according to the phases of the moon.
The most common moonstone comes from the mineral adularia. It is named after an original mining site near Mount Adular in Switzerland that supplied this gemstone. This location also gave rise to the term adularescence. This term refers to the milky glow of the stone, like moonlight rippling on water.
The moonstone is made up of tiny layers of astrium that scatter light and cause that wavy effect of adularescence. The thinner layers produce a bluish glow, while the thicker layers appear white. Moonstone gemstones come in a range of colors covering yellow, gray, green, blue, peach and pink, and sometimes display a star or cat's eye.
The most beautiful classic moonstones, colourless transparent with a blue glow, come from Sri Lanka. Since these sources of high quality blue moonstone are virtually exhausted, prices have risen sharply.
Moonstones are also found in India, Australia, Myanmar, Madagascar, Madagascar and the United States. Indian gemstones, which are brown, green or orange in colour, are more abundant and affordable than their classic blue counterparts.
The weakness of this beautiful gemstone is its relatively low hardness, 6 on the Mohs scale, which makes it prone to stress cracking and splitting. Caution is required with moonstone jewelry such as rings or bracelets; thus, sometimes pins and pendants are preferred for long-term durability.
Source: americangemsociety.org
