Silk is one of the oldest known textile fibres and, according to Chinese tradition, was used as long ago as the 27th century BC. The silkworm moth was originally a native of China, and for about 30 centuries the gathering and weaving of silk was a secret process, known only to the Chinese. China successfully guarded the secret until AD 300, when Japan, and later India, penetrated the secrecy. References in the Old Testament indicate that silk was known in biblical times in western Asia, from where it was presumably transplanted to the Greek Islands of the Aegean Sea. Caravans carried silk on camelback from the heart of Asia to Damascus, Syria, the marketplace at which East and West met. Here silk fabric was traded for Western luxuries, some of which survive in China today. Silk became a valuable commodity in both Greece and Rome. Until AD 550 all raw silk and silk woven in Europe was derived from Asiatic sources. With the spread of Islam, the silkworm came to Sicily and Spain. In India silk fabric was widely used at different ceremonies and was highly appreciated by people. India was one of the first countries to succeed in weaving both silk and cotton. For centuries silk was considered to be the fabric of royalty. Sericulture, or the raising of silkworms, involves the incubation of the tiny eggs of the silkworm moth until they hatch and become worms. After hatching, the worms are placed under a layer of gauze. For six weeks, the worms eat finely chopped mulberry leaves almost continuously. At the end of this period, they are ready to spin their cocoons, and branches of trees or shrubs are placed in their rearing houses. The amount of usable silk in each cocoon is small, and about 5,500 silkworms are required to produce 1 kg (2.2 lb) of raw silk out of which silk fabric is produced. Silk is produced by a number of insects. It is worthy of note that spiders' nests are also called "silk". Silk, as well as wool, is a fabric of animal origin. The worms producing silk fabric are spread all over India. There exist different kinds of silk. One of them is brocade which is obtained by means of combining colored silk with gold threads. In order to use the cloth during religious ceremonies they can weave Hindu or the Koran verses into the tissue. Silk weaving in India is an industry which is based mostly on handcraft. Two weavers working at a loom manage to produce about two silk saris in a month. There are a many silk varieties in India. Designers say almost every one of them can be manufactured into garments. And it is not only Indian saris that are made of silk. Silk fabric can be used for sewing various flowing shirts, mini dresses, kimono, pants and a lot of other garments. In structured clothes raw silk, silk interwovened with cotton and brocade or tasar are used. Another kind of silk is chanderi. It is famous for its transparency and even can't be compared to silk organza, chiffon, crepe-de-chine and others. Today, one of the most popular tendencies is silk combined with embroidery. Silk fabric is used not only for garments but also for quilt, cushions, curtains, bedcovers and even table cloths. As a rule there are three crops of cocoons every year. Silk can be of two kinds: it is pure silk and blended one. India gets large orders from highly fashionable stores in the United States of America and Europe. As a rule Europe orders raw silk suits, jackets, blouses, skirts and furnishings. As for America and Australia, they import satin silk and crepe silk saris. The most popular colors of silk now are different shades of red, scarlet, pink and magenta. Such colors as purple, yellow, emerald green, electric blue and some other jewel colors are also of great demand.