The word 宝石 is formed by combining two meaningful characters: 宝 (bǎo), which means "treasure" or "precious", and 石 (shí), which means "stone". The formation is purely conceptual, where the essence of the first character modifies and elevates the category of the second. By joining them, the concept transforms from a general "stone" into the specific and valued idea of a "precious stone" or "gem". It is a direct compound where the combined meaning is intuitively greater than the sum of its parts.