Obsidian is an stone-age metal-like Resource. It is available from the beginning of the game and does not require research to be mined.

Obsidian can be uncommonly found on any Climate. It is extracted using the Flint collector and it is used by the Weapon maker to make Macanas and Topillis, or by the Jewelry Maker to make Adornments.

Obsidian can be used to recruit the high-tier stone age units Pitsotl and Eagle Warrior. These units are fairly effective until the mid Copper Age and are relatively cheap to recruit.

While moderately useful, obsidian is not usually considered essential, or actively sought after by experienced players. Adornments require too much obsidian for obsidian outposts to be useful, while obsidian units are only moderately useful for a relatively short amount of time.