Master Gems have one purpose: To provide a 100% success rate at capturing enemy monsters.
Currently, all Master Gems must be purchased with Diamonds
Master Gems come in multiple varieties, and each can only be used for it's intended purpose.
Common Gem[]
Common Gems can be purchased in battle for 10 Diamonds, and can be used to capture a Common Monster
Common Gem
Rare Gem[]
Rare Gems can be purchased in battle for 50 Diamonds, and can be used to capture a Rare Monster
Rare Gem
Epic Gem[]
Epic Gems can be purchased in battle for 100 Diamonds, and can be used to capture an Epic Monster
Epic Gem
Ultra Gem[]
Ultra Gems can be purchased in battle for 150 Diamonds, and can be used to capture an Ultra Monster
Ultra Gem
Legendary Gem[]
Legendary Gems can be purchased in battle for 200 Diamonds, and can be used to capture a Legendary Monster
Legendary Gem