Gemstone Classification First, we must learn how gemstones are grouped in order to understand their grading system. Gemstone beads are classified by three main categories: Precious gemstones exclusively allude to Diamonds, Rubies, Sapphires, and Emeralds. Synthetic gemstones are manmade stones such as Opalite and Goldstone. Lastly, semi-precious gemstone beads refer to all other gemstones that … Continue Reading
