Asth'issa, Queen of Gems

Flying
Whenever Asth'issa, Queen of Gems attacks,
create a Gem token of a color of your choice. (It's
an artifact with "{t}, Sacrifice this artifact: Add one
mana of this artifact's color.")
Gems you control are all colors.
Whenever you sacrifice a gem, put a +1/+1
counter on Asth'issa.