Obsidian

Obsidian is a vanilla block obtainable in the Obsidian Sanctuary and The End, and also through Minions.

Obtaining
Obsidian naturally generates in the Obsidian Sanctuary and The End. Mining Obsidian with a Diamond Pickaxe grants +20 Mining XP. Obsidian can also be generated on the Player's Island by having Water flow over a Lava source block, or it can be made by dumping Lava into the corner of a 2x2 pool of water.

Obsidian can also be obtained via killing an Obsidian Defender in The End. It can also be obtained through the Nether Wart Island, which is unlocked through Netherrack collection. All these ways contribute to the Obsidian Collection.

Usage
Obsidian can be used in several crafting recipes in the Obsidian collection, including the Obsidian Minion.

Obsidian can be sold to any Merchant for 12 Coins per.

Obsidian can be used to brew Stun Potions.