Definition: Luster on a coin's surface is the sheen or reflective qualities that are produced during the minting process. When a coin is struck, metal flows from the center of the coin towards the outer edge. This process produces microscopic striations (very tiny parallel grooves) that reflect light back to the viewer in a unique crossing pattern. As the coin is tilted under a light, this crossing pattern will spin around the coin. This is known as the cartwheel effect.
Also Known As: mint luster, cartwheel effect
Alternate Spellings: lustre
Examples:
The luster on this coin indicates that it is in uncirculated condition.
