You can find most popular coin collecting phrases in this coin glossary.
bag mark - Mark(s) on a coin that occurred during the production process. Come from coins bumping into each other when placed in bags at the mint. Larger size coins typically exhibit more bag marks than smaller ones. A coin can still be un-circulated even if it has obvious bag marks. bar - usually an "ingot" shaped as a rectangle. Can be gold, silver, or any precious metal. Gold and silver bars vary in size from 1 gram up to thousands of ounces.
barber - nick name for US dimes, quarters, and half dollars designed by Charles E. Barber. They depict a “liberty head” on the front (obverse) and a eagle with shield on the reverse.bid - the price a dealer (or dealers) are offering to pay for a coin. Sometimes used to indicate a standing offer at that price from a coin dealer or on a trading network. Also, see "site unseen".
billon - a low grade of silver. Although sometimes silver in color, usually made of part silver and part copper.
bit - slang used to indicate one eighth of a dollar. In early days of this countries history the Spanish Milled Dollar (pillar dollar or 8 reales) circulated. Due to a shortage of smaller coins these silver dollars were often cut into pieces shaped like slices of pizza. A small piece equal to one eighth of the dollar was called a "piece of eight" or a "bit". The nursery rime "two bits, four bits, 6 bits, a dollar" comes from this time in history." Example, two bits = two eighths or a quarter.
blank - a blank piece of metal on which a coin design can be stamped. Also called a planchlet (planchet). Usually already cut into the shape of a coin - but without any design.