Silver Key (The Submarine)
The Silver Key is a key found in the level The Submarine in Tomb Raider Chronicles. The key is found in a storeroom where Lara is able to go after unlocking the door with a bronze key that she gets from the submarine's cook. The same storeroom also holds the pistols.
The Silver Key is used to unlock a door in the kitchen that leads further into the submarine.
There are other Silver Keys in the Russia section: two keys are found in the level The Base, another key is found in the level Sinking Submarine.