In Diablo 2 Resurrected, aside from D2R Ladder Runes and Runewords, gems are one of the most important items that you'll need to further develop your character. You can use them in socketed items and enjoy magical additional effects. In this guide, we'll introduce you to the types of gems, how to upgrade them, and what they can be used for. 1. Types of Gems  There are seven...