What does the term "parti-colored" refer to in gemstones?

The term "parti-colored" refers to gemstones that exhibit color zoning or a combination of two or more distinct colors within the same stone. This characteristic is particularly admired in certain types of gemstones, such as tourmaline and sapphire, where the color variations can create a unique and visually striking appearance. These variations can occur in bands, sections, or patches, contributing to the gem's individuality and charm. The presence of multiple colors enhances the stone's beauty and can affect its value depending on the colors' arrangement and intensity. Understanding this terminology is essential for identifying and appreciating the qualities that make certain colored stones desirable to collectors and jewelers alike.