In Aion, there are three basic ways to enchant your gear. The first is using Enchantment stones, the second is using Manastones, and the third is using Godstones.
Manastones
Manastones contain a certain statistic and a certain value. For example, Manastone: Accuracy +12. In this case, this Manastone would add 12 to your Accuracy value if you placed it into a socket of one of your equipped items. Similar to the Enchantment stones, only the following slots contain sockets: chest slot, legs slot, shoulders slot, hands slot, feet slot, primary slot, and secondary slot. Also, the higher the rarity of the item, the more sockets it contains.