What is the main component of dental amalgam by weight percentage?

Dental amalgam is composed of approximately 50% mercury (by weight) mixed with an alloy powder containing primarily silver (25-35%), tin (12-14%), and copper (0-30% depending on whether it is a high-copper or low-copper alloy). Mercury provides the plasticity needed to manipulate the material during placement. The mercury reacts with the alloy particles to form intermetallic compounds (gamma-1 and gamma-2 phases), producing a hard, durable restoration. High-copper amalgams (copper greater than 6%) have improved corrosion resistance because the high copper content eliminates the weaker gamma-2 (Sn-Hg) phase. Despite concerns about mercury toxicity, the chemically bound mercury in set amalgam is considered safe by most regulatory bodies.