What aspect of gemstones does hardness measure?

Hardness in gemstones specifically measures their resistance to scratches. This property is a crucial aspect of a gemstone's durability and is typically assessed using the Mohs scale of mineral hardness, which ranks minerals from 1 (talc) to 10 (diamond). A gemstone with a high hardness rating can withstand more wear and tear without being scratched by other materials, making it more suitable for everyday wear in jewelry.

For instance, a diamond, which is the hardest known natural material, can only be scratched by another diamond. This characteristic significantly influences how gemstones are used in jewelry, particularly for pieces that are subject to daily use. Understanding hardness is essential for gemologists and jewelers to recommend appropriate stones for different types of jewelry based on their intended use and expected wear.