> For the complete documentation index, see [llms.txt](https://zombecoin.gitbook.io/zombiecoin-whitepaper/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://zombecoin.gitbook.io/zombiecoin-whitepaper/precious-stones.md).

# Precious Stones

Precious Stone can be found by Zombie Miners while mining and Pets while hunting. Precious Stones are used for crafting and to upgrade tools.

1. Emerald: used to upgrade tools to level 2+
2. Rubi: used to upgrade tools to level 3+
3. Sapphire: used to upgrade tools to level 4+
4. Diamond: used to upgrade tools to level 5