Silver

Silver ore is added by several of the major tech mods Thermal Expansion, Factorization, IndustrialCraft 2, GregTech and RedPower 2. Silver Ingots are used in many crafting recipes.

Processing
Silver ore can be smelted using any smelting machine or furnace.

Smelting
To double or even triple your ore out put you will need to use one of the processing machines. The dust from these machines will need to be smelted in a smelting machine or furnace.

Thermal Expansion 3
Silver can also be made by using Factorization's Slag Furnace, and putting either Silver Ore in, or any other of the Factorization ore processing chain items.

Uses
Silver can be made into Ingots or Dust after which point it can be converted in to Nuggets or Storage Blocks It is also used to make Electrum Ingot

World Generation
Thermal Expansion, Factorization, GregTech and RedPower 2 all generate some from of Silver Ore. Although IndustrialCraft 2 has a processing chain for Silver and recipes requiring it, it does not add Silver Ore itself.

Ore world generation is controlled in the config files of the mods that add it. To have only one type of an ore generated turn off the ore generation in the config files for all but 1 of the mods. CoFH Core offers you the ability to tweak the spawn rate of all modded and vanilla ores.

Immersive Engineering
Silver can be used to create the Silver Cartridge.