PLANETARY - Of, relating to, or resembling the physical or orbital characteristics of a planet or the planets.
PLEOCHROISM - A gemstone changes color, depending on the angle it is viewed at.
POLISHING- Gemstones are usually polished to a mirror-like finish to aid light reflection from the surface of the stone (or refraction through the stone, in the case of transparent materials).
PRECIOUS - The common precious gemstones are diamonds, rubies, sapphires, and emeralds.
PREFORM - An object that has been subjected to preliminary, usually incomplete shaping or molding before undergoing complete or final processing.
