From https://opengameart.org/content/painterly-spell-icons-part-2

License(s): 
CC-BY 3.0
CC-BY-SA 3.0
GPL 2.0

Copyright/Attribution Notice: 
J. W. Bjerk (eleazzaar) -- www.jwbjerk.com/art -- find this and other open art at: http://opengameart.org

Thanks!