June is a great month to celebrate the pearl, the first birthstone of summer and a one of nature’s most beautiful flukes.   Natural pearl formation begins when a pearl-bearing mullosk’s shell reacts to a foreign particle landing inside its soft tissue and causing irritation. The mullosk tries to reduce the irritation by coating the invader with nacre -- also known as mother of pearl -- an organic-inorganic composite material produced by some mollusks as an inner shell layer. Nacre is also what makes up the outer coating of pearls; it is very strong, resilient, and iridescent.   Nacre provides the pearl with its shine, or luster, and the bigger the pearl, the more nacre – and thus, the more luster.   Natural pearls have been valued for more than 4,000 years; One of the favorite gems of the Roman Empire, the Tudor Empire of the 16^th Century was known as the Pearl Age.   Pearls are the only gemstones that are harvested from living sea creatures, and require no faceting or polishing to reveal their natural beauty.   Round saltwater pearls were first cultivated commercially in the late 1800s, and since the 1920s, cultured pearls have all but replaced natural pearls in the world’s gem market.   The culturing process  allows for a whole pearl to be grown from mantle tissue piece and a bead nucleus inserted into a host mollusk’s gonad,  replicating nature’s process for pearl growing.                  If you’re purchasing pearl jewelry for your June birthday girl, there are some factors you should keep in mind:  

1. Size: bigger is better, since the bigger the pearl, the better the luster.
2. The value of a pearl is measured by its ability to absorb, refract and reflect light, imparting  a distinctive quality (termed orient) to natural and cultured pearls.
3. Orient is the deep inner glow and shimmering iridescent characteristic of a sea-grown pearl. The deeper the lustre and iridescence, the more precious the pearl.
4. The more symmetrical the shape, the more valuable. Symmetrical pearls can be round, oval, pear shape or  tear shape. Baroque pearls are irregular and asymmetrically shaped. Oysters grow pearls in many different shapes, from perfect spheres to long flat angel wing pearls.
5. Surface perfection contributes to value. The surface of a perfect pearl appears satiny smooth. But when viewed closely, natural or cultured pearls may appear to have irregular surfaces which do not detract from value like disfiguring blemishes.
6. Rarity increases the value of any jewel. A perfect pair of pearls is very rare, since nature makes few pearls exactly alike in orient, size, shape and color.

  Nacre gives pearls their natural color -  generally pink, white, silver, gray, yellow, brown or gold. The  color of the pearl is often complemented by the rainbow iridescent appearance of the pearl’s orient.   Since pearls are naturally porous, they’re easy to die. Jewelry makers are now offering pearls in a wide variety of exquisite colors, with each pearl dyed to match for a perfect strand.   Harmless gamma-ray irradiation darkens the nucleus, resulting in a darker pearls that may resemble natural black South Seas pearls, but are more affordable.  Irradiation also enhances orient in some pearls, adding to their iridescence.   There’s plenty of beautiful jewelry options for your June birthday girl, and you can add to her pearl collection over the years.   ###