Since the question always comes up about breeding Gold Nuggets I thought I'd post the only write-up i've seen with pictures.
http://translate.google.com/translate?sourceid=navclient&hl=en&u=http://www.welse.ch/portal/Berichte/ZuchtberichtL177/tabid/345/Default.aspx
http://translate.google.com/translate?sourceid=navclient&hl=en&u=http://www.welse.ch/portal/Berichte/ZuchtberichtL177/tabid/345/Default.aspx