The fifth generation amalgam included?
The alloying of silver, copper, tin and indium together creating a quaternary alloy in which almost none of the tin is available to react with the mercury when mixed with the powder, was the 5th generation amalgam to be developed.
Reference: Marzouk Operative dentistry, pg-106
Silver, copper, tin
Silver, copper, zinc, tin, indium
Silver, copper, tin, indium
Silver, copper, tin, palladium