Obsidian

Obsidian is a type of block found in the update 0.28_01. It's color is dark purple and dark blue, it's sort of like the bedrock, but its main color is purple.

Obsidian is never to be found in a generated map, though it was originally thought that obsidian was cooled lava, which could emerge if it collides with water. Obsidian is a great block to use for art, especially when you use a lot of black.

In Survival mode, Obsidian takes longer to mine than any other material. Unfortunately it only gives you one cobblestone block.

Currently in Infdev, obsidian blocks are used to mark the positions of the cardinal directions. This creates two intersecting planes extending just above the surface of the solid material that surrounds them.

Obsidian may cause things to float.