: Hardness and specific gravity are primary factors used to classify stones into precious and semiprecious categories. 2. Optical Phenomena
Where ( n ) is the refractive index (RI). age18a physics of gemstones
Gemstones are crystalline solids, meaning that their atoms are arranged in a repeating pattern called a crystal lattice. This lattice structure is responsible for the stone's optical, electrical, and magnetic properties. The crystal structure of a gemstone is determined by its chemical composition, temperature, and pressure conditions during formation. : Hardness and specific gravity are primary factors