What defines a gem variety?

A gem variety is defined as a subcategory based on specific characteristics such as color, transparency, inclusions, and other distinctive traits that differentiate one type of gemstone from another within the same species. For example, within the species corundum, the varieties include ruby and sapphire, which are classified not by their chemical composition but rather by their specific colors and sometimes particular properties.

This definition captures the complexities of how gemstones are categorized and helps gemologists and jewelers communicate effectively about different types of stones. The specific characteristics considered can include hue, saturation, tone, and additional features that contribute to a gem's overall identity. Thus, understanding gem varieties enables better identification, valuation, and appreciation of gemstones in the context of jewelry and collecting.