Starlight gems produce energy according to the level of the gem. Level 0 seems to be able to produce 7 energy. As the level of the gem increases, it produces more energy. Up to level 10, it produces about 250 energy. I just I have fought with people who have level 10 starlight gems, but they are not my own, so I cannot be sure that level 5 gems can produce 175 energy. I can be sure that I am a level 5 gem now