Amber is fossilized tree resin (not sap), which has been appreciated for its color and natural beauty since Neolithic times. Much valued from antiquity to the present as a gemstone, amber is made into a variety of decorative objects. Amber is used as an ingredient in perfumes, as a healing agent in folk medicine, and as jewelry. There are five classes of amber, defined on the basis of their chemical constituents. Because it originates as a soft, sticky tree resin, amber sometimes contains animal and plant material as inclusions. Amber occurring in coal seams is also called resinite, and the term ambrite is applied to that found specifically within New Zealand coal seams.
With some exceptions, such as watches, medical alert bracelets or military dog tags, jewellery normally differs from other items of personal adornment in that it has no other purpose than to look appealing, but humans have been producing and wearing it for a long time – with 100,000-year-old beads made from Nassarius shells thought to be the oldest known jewellery.