A Golden Crystal is an enchanting crystal that can be used on an enchanted forge on any enchantable item. This gem will modify any weapon to increase the base damage or effect on a successful hit (physical damage for most swords; special ones such as Oozing Blade have their acid effect increased) as well as modify any armor to have a 5% increase in all resistances.
This item was introduced in Geneforge 3 and has stayed in the game ever since. The icon is the same used in the Runed Onyx but has a different color. Golden Crystals are popular due to their increase in Hostile Resistance effect, however as they are the highest-valued crystal, they are rare to find.