References: Palache, C., Berman, H., & Frondel, C. (1951), The System of Mineralogy of James Dwight Dana and Edward Salisbury Dana, Yale University 1837-1892, Volume II: 831.
GR56-AFM (1989), Mines de Huelgoat, Le Cahier des Micromonteurs, n°1, pp: 21-45
http://www.strahlen.org/vp/fr/huelgoat/62 entries listed. 51 valid minerals. 2 type localities (valid minerals).