Attributes are elemental strengths and weaknesses that help or hinder you depending on the environment; these are changed with a Gem of the same(or higher) rarity.

AttributeStrong against (+25% damage)Weak against (-25% damage)
NatureWaterFire, Poison
FirePoison, NatureWater
WaterPoison, FireLightning
PoisonNatureFire, Water
MagicChanges element each reload-


Gems are used for applying an attribute to your weapon. Keep in mind that You cannot apply a gem to a gun if it is a lower rarity than it.
This means, if you want to put a gem on a RARE gun, you need a RARE OR ABOVE gem.
MYTHIC rarity of gem can be applied on ANY RARITY gun.
To upgrade gems, you use Gem Fragments.