Colloidal Silver is pure, metallic silver, in particles of 15 atoms or fewer, each with a positive electric charge. These electrically charged particles of silver are extremely small, usually ranging from about 1-10 Nanometers (0.001 to about 0.01 microns) in diameter, and are suspended in pharmaceutical grade water. The force of the electric charge is stronger than the force of gravity, so the silver particles remain suspended.