The oysters are nucleated with a bead composed of mother-of-pearl and a small piece of mantle tissue. This bead becomes the nucleus of the pearl and is the reason akoya pearls are more often perfectly round.
Carbon definition, Chemistry. a widely distributed element that forms organic compounds in combination with hydrogen, oxygen, etc., and that occurs in a pure state as diamond and graphite, and in an impure state as charcoal.
Carbon tetrachloride (Carbon tet) is a non-flammable colorless liquid with a heavy, sweet odor.Before 1970, carbon tet was widely used as a cleaning fluid in home and industry. Until 1986, the chemical was used as a grain fumigant. Carbon tet is still used to manufacture propellants and other industrial chemicals.arbon tetrachloride (Carbon tet) is a non-flammable colorless liquid with a heavy, sweet odor.