Meteorite

Obtained from meteorite crash sites (caused by breaking a Shadow Orb), requires a Gold Pickaxe or higher to mine. The meteorite, once fallen, can be located in almost any place in the world map, even underwater at the edges of the map, so every inch of the surface should be scoured when the meteorite lands to find it.

Due to being available in large amounts (once available at all), six are required to make a Meteorite Bar.

Use caution when mining as contact with the stone itself causes damage unless equipped with an Obsidian Skull. The area is also guarded by Meteor Heads. You do not really need an Obsidian Skull to mine this rock, but it is recommended.

A good way to mine it all fast is to just chuck a couple sticks of Dynamite or a couple of Bombs. This will most likely stop the spawning of Meteor Heads as they will only spawn as long as there is at least 50 Meteorite blocks in the area. You will tell when you have removed the certain amount of blocks when the music changes back to normal.

A player could also equip a Cobalt Shield and let the Meteor Heads to hit them while mining. A player can also get all the meteor heads on one side and then mine while keeping the meteor heads away with knockback by hitting them with a pickaxe.