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Birthstones
Michael Schweska
Physical Geology
Spring 2005
 

                                        June Birthstone-Pearl

 
Pearls Pearl is the official birthstone for the month of June as adopted by the American National Association of Jewelers in 1912. Fresh water pearls are given on the 1st wedding anniversary. Pearls are also given on the 3rd, 12th and 30th anniversaries. Pearls are quite "soft" and range between 2.5 and 4.5 on the Mohs scale of hardness. They should be protected from extreme wear. Natural pearls have been harvested from the Persian Gulf, the Gulf of Manaar (Indian Ocean), and the Red Sea for thousands of years. The coasts of Polynesia and Australia produce mainly cultured pearls. Both freshwater and saltwater pearls are cultivated in Japan and China. Freshwater pearls occur in the rivers of Scotland, Ireland, France, Austria, Germany, and the USA (Mississippi). Click here for a picture in natural form. Click here for more cultured and natural specimens.

Description:

Pearls vary in color from white to those with a hint of color, often pink, to brown or black. Each coloration will depend on the type of mollusk and the water where the mollusk lived. The most valuable pearls are perfectly symmetrical, relatively large and naturally produced. They have a shimmering iridescence which is called orient luster. Because the nacre is organic, pearls are very sensitive to extreme heat, acids, dryness, and humidity. Care should be taken when storing them. Ultrasonic cleaners are great for cleaning some jewelry but is not recommended for pearls.

Chemistry:

An organic gem, pearls are formed inside mollusks such as oysters and mussels. They are formed when an irritant such as a tiny stone or bit of sand gets inside the mollusk's shell. A lustrous substance, called nacre, is secreted around the object to protect the soft internal surface of the mollusk. As layer upon layer of nacre coats the irritant, a pearl is formed. Light that is reflected from these overlapping layers produces a characteristic iridescent luster. This process of building a solid pearl can take up to seven or eight years. The principal oyster beds lay in the Persian Gulf, along the coasts of India and Sri Lanka, and in the Red Sea. Chinese pearls come mainly from freshwater rivers and ponds, whereas Japanese pearls are found near the coast in salt water.

There are many types of pearls:

 
  • natural pearls (made with no human interference),
  • cultured pearls (made when a human intentionally inserts foreign tissue into a living oyster),
  • baroque pearls (irregularly-shaped pearls), freshwater pearls, seed pearls,
  • Biwa pearls (a freshwater pearl from Lake Biwa, Japan),
  • blister pearls (grown attached to the shell),
  • black pearls (gray to black pearls),
  • Mabe pearls (cultivated blister pearls).

Legends, Myths and Healing Properties:

PearlsCultured or freshwater pearls are considered to offer the power of love, money, protection, and luck. Pearls are thought to give wisdom through experience, to quicken the laws of karma and to cement engagements and love relationships. They are thought to keep children safe. Early Chinese myths told of pearls falling from the sky when dragons fought. Ancient legend says that pearls were thought to be the tears of the gods and the Greeks believed that wearing pearls would promote marital bliss and prevent newlywed women from crying. During the Crusades in the Middle Ages, pearls were the gift of choice for a knight to give to his lady. During the 14th and 15th centuries, royal wedding scenes closely resembled a sea of pearls, with everyone from the bride down to her male guests adorned with impressive arrays of pearl jewelry.