Simiel is the name of an angel archangel (formed with the theophoric Hebrew suffix -el, "God"), cited by Pope
Gregory I and probably made over the Hebrew name Samael.
In Mexico, there was a town called Simiel-Tepeque, not related with the first name Simiel (I don't have the etymology for Simiel):
http://www.ejournal.unam.mx/ehn/ehn26/EHN02605.pdf
Lumia
http://onomastica.mailcatala.com