From Dark and Darker Wiki
https://darkanddarker.wiki.spellsandguns.com/Utility https://darkanddarker.wiki.spellsandguns.com/Mystical_Gem
The mystical gem can be found on the utilities page, it also has it's own page. Above are the links to them.
( 神秘的宝石可以在实用程序页面上找到，它也有自己的页面。上面是它们的链接。 （这是谷歌翻译的）)