Ore

Ores are rare stone blocks used to obtain resources.

Usage
Ores are primarily collected for crafting purposes, such as for tools and armor. Redstone is obtained from redstone ore, which can be used to create redstone circuits. Ore can also be combined to create a block of the material's type. Obtaining resources from ores is as simple as mining them (this is not the case for iron and gold ores, which must be smelted). Coal, diamond, emerald, and nether quartz ores drop 1 unit corresponding raw materials. Redstone ore drops 4-5 redstone dust, and lapis lazuli ore drops 4-8 lapis lazuli. Note this can be increased greatly with fortune. All ore blocks except iron and gold require a Silk Touch pickaxe to drop themselves.

Further uses
All mineral blocks except quartz are crafted by putting 9 of the raw material items in a square. Quartz blocks are irreversibly crafted with 4 nether quartz and can be crafted in the inventory.

All raw materials except quartz can be crafted from their mineral blocks.

Availability
The following is the distribution of ores according to the altitude (layers are number of blocks above the lowest layer of bedrock). The highest layers that gold, redstone, diamond, and lapis lazuli can be found on are two layers lower. The graph on the right shows the ore distribution. More graphs can be found on reddit.

Redstone has the same layer and line-size statistics as Diamond, but is generated 8 times per chunk as opposed to 1.