During many centuries the pearls were perceived as a gift of nature and destiny and traditionally ranked as jewels.
Ancient Greeks believed that nacreous stones are the nymphs’ solidified tears. Like nymphs, the special sort of molluscs-zhemchuzhnits lives in the warm seas: at the coast of Arabian peninsula, Ceylon, Northwest Australia, Southern Burma, many islands of Pacific Ocean, Central and the South America, Japan. In Europe collected river pearls: first of all in Russia, England, and Ireland. When the alien body occurs inside the shell, for example a grain of sand, zhemchuzhnitsa perceives it as a trauma and starts to “cry” with nacreous tears, enveloping an alien subject with the aragonite layers. So the pearls are born. During 2-3 years the oyster increases round the object a layer in 5 mm. To grow up a pearl of the average size is required nearly 3-4 years, large – 12 years, huge – more than 200.
Color chart
white
peach
pink
grey
black
Colour of pearls depends on the impurities in the aragonite, and also from the degree of the transparency of an external cover and the character of a spreading layer. In nature the pearl amazes with its variety of forms and colours. A colour variety of “nacreous stones” fluctuates from rich-black and green from Gulf of Mexico islands and Tahiti to bright-pink – from California gulf, silver and yellow – at coast of Ceylon, pale-green – in Japan and white – in Australia. Shades are countlessly. Depending on the size, the pearls are subdivided on high-quality – more than 3 mm, beads – 3-2 mm and a pearl dust – less than 2 mm. According to the form, colour and shine there are 3 classes of pearls: I class – absolutely round, white with strong shine, with a weak bluish or pinkish shade; drop-shaped, the faultless form are equated to the round; II class – not ideally round (pear-shaped, oval, slightly flattened), white with strong shine and absolutely round white with weak shine; III class – all pearls with weak shine which are suitable for manufacturing of jewellery at least in small degree.
Colour of pearls has its price: it is considered the most expensive is bright-pink and black, and the cheapest is yellow. As pearl’s unit of weight it is accepted pearl gran – remained in gemology for measuring of pearl’s weight, the stand-alone unit equal of 50 mg (0,25 carats).
Today distinguish three kinds of pearls: natural – it is formed without participation of the man, cultivated – the alien body is put into the mollusk’s shell by the man, and artificial.