Silver Coin
Silver Coins are coins that only appear when a P-Switch has been pressed, and will disappear once the P-Switch wears off.
Silver Coins first appeared in Super Mario Bros. 3, where they appeared out of thin air in certain spots for as long as a P-Switch was in effect. Silver Coins have the same value as standard Gold Coins, and are usually found in clusters.
In Super Mario World, pressing a Silver P-Switch would turn all enemies in Silver Coins for a limited time. However, Silver Coins worked differently from standard coins in this game; if enough were collected, they would start racking up into extra lives, similar to jumping on numerous enemies in succession. In certain levels, a trick involving hordes of enemies and a Silver P-Switch can be executed to earn dozens of extra lives.
They appear in New Super Mario Bros., having the same role as in Super Mario Bros. 3. They sometimes appear in a trail behind Invincible Mario in a few levels, like World 7-3.
