Necklaces
Strictly speaking, a necklace is a piece of jewelry consisting of a string of stones, beads, gemstones, or a chain for wearing around the neck. Pearls threaded together on a silk string (i.e., a "string" of pearls) represent a classic example of this. Today's interpretation of a necklace can take on many forms and consist of any number of different materials, which are not always precious or intrinsically valuable. The shapes and pieces fused, strung, fastened or interwoven to form the circle of a necklace are virtually limitless.
Chains
In the jewelry world, a chain can be either an essential component of a more complicated necklace, or it can actually be the necklace all by itself. Most chains and chain necklaces sold as fine jewelry are made of one of the precious metals: platinum, gold or sterling silver.
Pendants
Both necklaces and pendants are jewelry worn around your neck. However, a pendant features a removable gem or jewelry accent that hangs from a chain, while a necklace has a gem(s) or accent(s) permanently attached. They are available in an almost limitless number of different shapes and styles, defined mostly by the type of ornament being used, although chain style is also an essential design element.