^Hudson, Richard Dennis; Hudson, Richard; Hudson, Rick (1999). A Field Guide to Gold, Gemstone and Mineral Sites of British Columbia. Orca Book Publishers. p. 7. The change can be small (slate is simply shale that has been cooked for a few millennia), or it can be so dramatic you can't tell what the original material was (sometimes known as fubarite = “fudged up beyond all recognition”)!