Natural Pearls:
A grain of sand or other irritant (nucleus) accidentally becomes lodged in the
soft inner body of an oyster, where it cannot be expelled. To protect itself,
the oyster secretes a smooth, hard, crystalline substance around the object
(nacre), forming, over a period of years, a pearl, usually of irregular shape.
Cultured
Pearls:
The process is very much the same as previously illustrated, but the nucleus is
inserted by man rather than nature. This
allows for a spherical object to be inserted thus creating perfectly round
pearls.
Lustre is a blend of surface brilliance and inner glow. A high-quality pearl will have a bright lustre, and your reflection should be seen clearly on the pearl's surface. A pearl that looks dull or chalky indicates low quality.
Surface:
A clean pearl surface should be free of disfiguring spots, bumps, or cracks. Both natural or cultured pearls are expected
to have some imperfections, but the fewer and less noticeable they are, the
better.
Shape:
Because pearls are grown naturally, a perfectly round pearl is extremely rare. They
range from round (the rarest and most expensive) to baroque (most common and
cheaper)
Colour:
Cultured pearls come in a vast colour spectrum ranging from white through
champagne, pink to black
Size:
Cultured pearls are measured by their diameter in millimetres. Generally, the
larger the pearl, the greater its value, however the average-sized pearl sold
today is between and 6 and 7 1/2 millimetres.
Caring for your Pearls:
Pearls
are more delicate than other gemstones, as they are porous and fairly soft. Cosmetics, perfume, and hair spray contain
chemicals that can harm pearls, so it's best to put on your pearls after you've
used these products. Wipe the pearls
with a soft, damp cloth after you wear them, and keep them separate from other
jewellery to prevent harder items from
scratching them.