Shell

Shell- A seashell or sea shell, also known simply as a shell, is a hard, protective outer layer created by an animal that lives in the sea. The shell is part of the body of the animal. Empty seashells are often found washed up on beaches by beachcombers. The shells are empty because the animal has died and the soft parts have been eaten by another animal or have rotted out.

The term seashell usually refers to the exoskeleton of an invertebrate (an animal without a backbone). Most shells that are found on beaches are the shells of marine mollusks ("molluscs" in British English), partly because many of these shells endure better than other seashells.

As currency
Seashells have been used as a medium of exchange in various places, including many Indian Ocean and Pacific Ocean islands, also in North America, Africa and the Caribbean.
 * The most common species of shells to be used as currency have been Cypraea moneta, the "money cowry", and certain tusk shells or dentalium, such as those used in North Western North America for many centuries.
 * Some tribes of the indigenous peoples of the Americas used shells for wampum and hair pipes. The Native American wampum belts were made of the shell of the quahog clam.
 * It is of historic interest that the Dutch East India Company, a major force in the colonization of the Indian and Pacific Oceans, amassed a large portion of its vast fortune via trading shell money of the species Cypraea moneta and Cypraea annulus, in exchange for commodities such as spices, exotic animals, and gemstones, all of which were considered valuable in Europe at the time.

As tools
Seashells have often been used as tools, because of their strength and the variety of their shapes.
 * Giant clams (Family Tridacnidae) have been used as bowls, and when big enough, even as bathtubs and baptismal fonts.
 * Melo melo, the "bailer volute", is so named because Native Australians used it to bail out their canoes.
 * Many different species of bivalves have been used as scrapers, blades, clasps, and other such tools, due to their shape.
 * Some marine gastropods have been used for oil lamps, the oil being poured in the aperture of the shell, and the siphonal canal serving as a holder for the wick.

In horticulture
Because seashells are in some areas a readily available bulk source of calcium carbonate, shells such as oyster shells are sometimes used as soil conditioners in horticulture. The shells are broken or ground into small pieces in order to have the desired effect of raising the pH and increasing the calcium content in the soil.

In religion and spirituality


Seashells have played a part in religion and spirituality, sometimes even as ritual objects.


 * In Christianity, the scallop shell is considered to be the symbol of Saint James the Great, see Pecten jacobaeus.
 * In Hinduism left-handed shells of Turbinella pyrum (the sacred shankha) are considered to be sacred to the god Vishnu. The person who finds a left-handed chank shell (one that coils to the left) is sacred to Vishnu, as well. The chank shell also plays an important role in Buddhism.
 * Cowries have often been considered to be symbols of female fertility. They were often treated as actual fertility charms. The dorsum of the shell resembles a pregnant belly, and the underside of the shell resembles a vulva. In the South Indian state of Kerala, cowries are used for making astrological predictions.
 * In Santería, shells are used for divination purposes.
 * The Moche culture of ancient Peru worshipped animals and the sea, and often depicted shells in their art.

As musical instruments


Seashells have been used as musical instruments, wind instruments for many hundreds if not thousands of years. Most often the shells of large sea snails are used, as trumpets, by cutting a hole in the spire of the shell, or cutting off the tip of the spire altogether. Various different kinds of large marine gastropod shells can be turned into "blowing shells", however the most commonly encountered species used as "conch" trumpets are:


 * The sacred chank, Turbinella pyrum, known in India as the shankha. In Tibet it is known as "dung-dkar".


 * The Triton shell also known as "Triton's trumpet" Charonia tritonis which is used as a trumpet in Melanesian and Polynesian culture and also in Korea and Japan. In Japan this kind of trumpet is known as the horagai. In Korea it is known as the nagak. In some Polynesian islands it is known as "pu".
 * The Queen Conch Strombus gigas, is or was sometimes used as a trumpet in the Caribbean.

In personal adornment
Whole seashells or parts of sea shells have been used as jewelry or in other forms of adornment since prehistoric times. Mother of pearl was historically primarily a seashell product, although more recently some mother of pearl comes from freshwater mussels. Also see pearl.


 * Shell necklaces have been found in Stone Age graves as far inland as the Dordogne Valley in France.
 * Seashells are often used whole and drilled, so that they can be threaded like beads, or cut into pieces of various shapes. Sometimes shells can be found that are already "drilled" by predatory snails of the family Naticidae. Fine whole shell necklaces were made by Tasmanian Aboriginal women for more than 2,600 years. The necklaces represent a significant cultural tradition which is still practised by Palawa women elders. The shells used include pearly green and blue-green maireener (rainbow kelp) shells, brown and white rice shells, black cats' teeth shells and pink button shells.
 * Naturally-occurring, beachworn, cone shell "tops" (the broken-off spire of the shell, which often has a hole worn at the tip) can function as beads without any further modification. In Hawaii these natural beads were traditionally collected from the beach drift in order to make puka shell jewelry. Since it is hard to obtain large quantities of naturally-occurring beachworn cone tops, almost all modern puka shell jewelry uses cheaper imitations, cut from thin shells of other species of mollusk, or even made of plastic.
 * Shells historically have been and still are made into, or incorporated into, necklaces, pendants, beads, earrings, buttons, brooches, rings, hair combs, belt buckles and other uses.
 * The shell of the large "bullmouth helmet" sea snail, scientific name Cypraecassis rufa, was historically, and still is, used to make valuable cameos.
 * Mother of pearl from many seashells including species in the family Trochidae, Turbinidae, Haliotidae, and various pearly bivalves, has often been used in jewelry, buttons, etc.
 * In London, Pearly Kings and Queens traditionally wear clothing covered in patterns made up of hundreds of "pearl buttons", in other words, buttons made of mother-of-pearl or nacre. In recent years however, the majority of "pearl buttons" are imitations that are made of pearlescent plastic.

In crafts
"Sailor's Valentines" were late 19th century decorative keepsakes which were made in the Caribbean, and which were often purchased by sailors to give to their loved ones back home for example in England. These valentines consisted of elaborate arrangements of small seashells glued into attractive symmetrical designs, which were encased on a wooden (usually octagonal) hinged box-frame. The patterns used often featured heart-shaped designs, or included a sentimental expression of love spelled out in small shells.

The making of shellwork artifacts is a practice of Aboriginal women from La Perouse in Sydney, New South Wales, dating back to the 19th century. Shellwork objects include baby shoes, jewelry boxes and replicas of famous landmarks, including the Sydney Harbour Bridge and the Sydney Opera House. The shellwork tradition began as an Aboriginal women's craft which was adapted and tailored to suit the tourist souvenir market, and which is now considered high art.

In architectural decoration
Small pieces of colored and iridescent shell have been used to create mosaics and inlays, which have been used to decorate walls, furniture and boxes. Large numbers of whole seashells, arranged to form patterns, have been used to decorate mirror frames, furniture and man-made grottos.