"Jewel quality" refers to the characteristics that determine the value and desirability of gemstones. Key factors include clarity, color, cut, and carat weight, often referred to as the "Four Cs." High-quality jewels exhibit excellent clarity with minimal inclusions, vibrant color, precise cut, and substantial carat weight. The grading of jewel quality is typically performed by professional gemologists using standardized criteria. Diamonds, sapphires, emeralds, and rubies are commonly assessed for their quality. Understanding these factors helps consumers make informed decisions when purchasing gemstones for jewelry or investment purposes.