Pearls_about

Pearls can dry and lose lustre if kept in a dry environment like a safety deposit box, for an extended period of time. They contain a small amount of water, so leaving them in a dry environment may cause their moisture to evaporate. Pearls worn frequently retain their moisture by absorbing it either from the wearer's body or from the air. Pearls are softer than other gems and should be handled with care.

(more on PEARL CARE below)

PEARL CARE:
1) Clean your pearls after wearing them to wipe away skin oils, perspiration, make-up, hairspray, perfume, or other impurities that can spot the surface. Body oils and acids can also damage the pearl's lustre. Use a mild soapy water to clean them. Do not use cleaning solvents or put them in an ultrasonic cleaner. Using a very soft, clean cloth is recommended after each use. You can also find a specially designed, patented pearl cleaning cloth (costs about $20.) A periodic deep cleaning by a professional jeweler is also recommended.

2) Put your pearls on last after you have finished applying make-up, perfume, and hair spray.

3) Protect your pearls from harmful chemicals, such as chlorine, alcohol, ammonia, vinegar, commercial jewelry cleaners, or from temperature extremes. All these things erode the luster of the pearl.

4) Avoid soaking your necklace in water as the pearls will absorb water from the silk thread and become stained or discolored. Taking a shower or bath with the pearls on is not encouraged. If they do become wet, lay the pearls out on towels for a few hours. The silk thread needs to dry out. Hanging them to dry will cause the silk threads to stretch.

5) Keep pearls away from other jewelry that may chip or scratch them, especially those made of metals. Store them separately in their own pouch or original presentation box. Pearls are knotted in between when strung, to protect the pearls from rubbing against each other. The knots also help secure the pearls in place in case the necklace or bracelet breaks.

6) After each use, wipe your pearls with a soft damp cloth to remove perspiration, make up, or perfume.

7) Allow pearls to breathe. Do not keep them in airtight plastic bag or safe. Store them in a soft cloth, pouch, or softly lined jewelry box.

8) Watch the silk threads carefully for discoloration and stretching. Pearls worn often should be restrung annually.

REAL OR FAUX?
Genuine pearls are formed by a crystalline substance in pearl oysters called "nacre" which is the lustrous outer shell. Fake pearls are manufactured from various chemicals, compounds, or by dipping a glass bead into a fish scale and lacquer substance several times. It gets its shine simply from surface reflection. A cultured pearl on the other hand, has a deep three-dimensional glow that emanates from within the pearl itself.

HOW TO TEST AUTHENTICITY OF PEARLS: THE VINEGAR & TEETH TESTS
Genuine pearls usually have tiny bumps in them. Putting a bit of vinegar on a genuine pearl will make it bubble. The nacre in pearls which is calcium carbonate, reacts to vinegar by producing bubbles. Fake pearls do not react to vinegar.

Another way to test is to rub the pearl gently against your teeth. If it feels sandy, it's real.

CULTURED OR NATURAL?
The main difference between cultured and natural pearls is in the thickness of the nacre. Natural pearls form without human help. A piece of shell or a parasite can accidentally settle in the soft inner body of the oyster where it cannot be expelled. Natural pearls are so rare nowadays that they are usually seen only in estate jewelry collections. The shape and position of the implanted nucleus determines the shape of the cultured pearl.

PEARL COLORS: If pearls seem to bright or colorful, it will unlikely to be a natural color. Generally, natural pearls come in cream, grey, off-white, bronze, pale pink and light lavender. Only a pearl with a hole in it can be dyed as the dye is absorbed from the inside underneath the nacre coating. White pearls are the most valuable. Coral pearls are quite rare. Two components comprise the make of a pearl - bodycolor and overtone. The overtone of a pearl is the color that overlies the bodycolor. These colors are either silver or rose. They are often found at finer stores like Mikimoto or Tiffany. Creamy pearls are worth 40% less than white pearls, according to the Gemological Institute of America (G.I.A.).To ensure the best value, purchase white pearls with rose or silver overtones.

TYPES OF PEARLS:
Akoya: A type of small oyster that lives in salt water in Japan and China. Akoya pearls are highly lustrous and very round. Akoya pearls larger than 9mm are rare. Biwa: Refers to freshwater pearls grown in Lake Biwa, a fresh water lake in Japan. Production at this location has ceased, but the name continues to be used to refer to a pearl produced in fresh water.

Freshwater: Pearls grown by mussels that live in fresh water rather than the ocean. Freshwater pearls are produced in a manner similar to salt water. Generally, the luster of freshwater pearls is not as deep or irridescent as salt water pearls. The quality of freshwater pearls from China has increased in recent years. Freshwater pearls are available in sizes up to 12mm.

Keishi: A name for freshwater pearls with irregular organic shapes. A pearl that formed against the shell of the oyster rather than in its flesh. As a result, the pearl is flat on the side that rested against the shell Mikimoto: A Japanese company that was among the first to begin culturing pearls. Today, Mikimoto uses both salt water and fresh water pearls from Japan and China.

Mikimoto has an excellent reputation for carefully matching the color and shape of their pearls.

South Seas: Refers to the oyster species found in the oceans of Southwest Asia. Pearls from Australian waters tend to be white, while those from Indonesia and he Philippines often have a natural golden color. South Seas pearls can be larger than Akoya pearls. Sizes range up to 14mm. Tahitian: A large salt water oyster native to the islands of French Polynesia.

Tahitian pearls are black in color, and on average larger than other pearl types. Both round and baroque shapes are highly prized.

NECKLACE LENGTHS:

Pearl Collar - 12 to 13 inches Usually made up of three or more strands that lie snugly on the middle of the neck.

Pearl Choker - 14 to 16 inches Complements almost any neckline, from button-down shirt to cocktail dress.

Princess Necklace - 17 to 19 inches Most common length for pearl necklaces, works well with both high and low necklines.

Matinee Necklace - 20 to 25 inches Looks best with high necklines, works with professional wear, long sundresses and formal gowns.

Opera Necklace - 26 to 36 inches Can be worn as a single strand with high neckines or doubled to create a two-strand choker. Works with evening wear and casual attire. Pearl Rope - 37 inches or longer Can be worn as a single strand tied with a knot, or doubled as a Princess length. Sometimes made with several clasps, forming different necklace and bracelet combinations.

sources:
http://www.americanpearl.com/faqq.html
http://www.pbs.org/wgbh/nova/pearl/time.html
http://www.pbs.org/wgbh/nova/teachers/viewing/2520_pearl.html
http://www.pearlparadise.com/pearlinformation.html