Amber, fossil resin or gum exuded from various, now-extinct coniferous trees. Transparent to translucent, amber is usually golden-yellow or yellow-brown in colour, although green, red, and black varieties have been found. It occurs as nodules, small irregular lumps, grains, or drops in geologically recent sediments deposited in shallow-water conditions. It is slightly brittle and emits an agreeable odour when rubbed. Amber burns with a bright flame and pleasant smell and becomes negatively charged by friction. (The word “electron” comes from elektron, the Greek word for amber.) Extinct and extant species of insects, leaves, and mosses are sometimes found encased in samples of amber. The most famous deposits, worked since antiquity, are found on the southern coast of the Baltic Sea. Known as succinite, Baltic amber has also been found washed up on the beaches of Norway, Denmark, and eastern England. Other noted occurrences are in Sicily and Myanmar (Burma); amber from these areas is known respectively as simetite and burmite. It is also found in small quantities in Romania, Siberia, Greenland, Mexico, Spain, the Dominican Republic, France, Australia, Canada, and the United States. Amber today is used primarily in the manufacture of jewellery, although historically it was also used to make ornaments and had a number of medicinal uses. It has been imitated by plastics, notably Bakelite, as well as by synthetic resins, and natural resins like copal.