What are rare nonmetallic minerals with extraordinary brilliance and color are also known as?

Rare nonmetallic minerals with extraordinary brilliance and color are commonly referred to as "gemstones." These minerals are prized for their aesthetic appeal and are often used in jewelry and decorative arts. Examples include diamonds, sapphires, and emeralds, each exhibiting unique hues and optical properties. Their rarity and beauty contribute to their high value in both cultural and economic contexts.