- Hadrian: "There. That should keep you quiet."
Mevia: "No one gets out of obsidian."
- —Hadrian and Mevia to Jesse. src
- In "The Order of the Stone", Jesse's gang travel to The Nether via a Nether Portal, constructed out of Obsidian.
- In the same episode, the Gang go to Gabriel's Temple, which is also made out of Obsidian.
- In "Assembly Required", there is a Nether Portal in Boom Town/Redstonia.
- In "The Last Place You Look", there are numerous Obsidian pillars in The End.
- In "Access Denied", PAMA's core room appears to be made out of Obsidian.
- In "A Journey's End?", Hadrian and Mevia use several blocks of Obsidian to build and to fight against Jesse.
- In "Jailhouse Block", the walls in the burrows are made of Obsidian. Some parts of the wall are later blown up by Creeders.
- Obsidian can only be broken using a Diamond Pickaxe.
- In Minecraft, even using a diamond pickaxe with Efficiency V, a block of obsidian still requires 2.55 seconds to crack; however, The Old Builders' diamond pickaxes crack Obsidian instantly, as shown by Jesse on the obsidian bridge.
- This implies they have a more powerful enchantment.
- Some mobs, such as creeders, are able to destroy obsidian.