Yes, do note they also have a mark on the nail of that finger, that mark is on the shape and color of their soul gem and it is true to lore, every meguca has a similar mark of the same nature on the finger they wear their soul gem ring, that mark also disappears while the girl is transformed, since the soul gem is elsewhere in those times.
There are a few more fun details about soul gem rings, they are meant to have the name of the girl who they belong to engraved onto them in Witch Runes, a detail very often omited both in fanart and official art because it is a really tiny detail that it is hard to make look good at a distance, plus the rings have a single jewel to them, but on the side of the girl's palm, the soul gem pops out of that jewel in egg form so that it is within the girl's grasp and they can grab it to be able to transform.
last edited at Mar 24, 2020 12:26AM