Lead Ore

Lead Ore is an early-game ore that generates upon world creation on the surface, as well as in the Underground and Cavern layers. Its primary use is in crafting Lead Bars, which can then be used to craft the Lead tier of tools, weapons, and armor, as well as Buckets, Chains, and several other items. The equivalent of Lead Ore is Iron Ore, which will sometimes replace Lead in a world. Lead Ore has a small chance to appear as a bonus drop from Slimes.

As Lead Bars are required to craft a Lead Anvil, Lead Ore must usually be obtained before any tools, weapons, or armor can be crafted from bars. While this can be circumvented by purchasing an Iron Anvil from the Merchant, that is generally inefficient, as it is not difficult to find 15 Lead Ore early on in the game.

Trivia

 * Lead Ore and Iron Ore are the only ores that do not have corresponding chandeliers. On the, they are also the only ores that do not have corresponding bricks.
 * Real is very soft and malleable, generally making it infeasible for crafting tools. The use of lead in Terraria more closely resembles real-life.