1) Monoclinic mineral 
Huttonite is a thorium nesosilicate mineral with the chemical formula {Thorium}{Silicon}{Oxygen}4 and which crystallizes in the monoclinic system. It is dimorphous with tetragonal thorite, and isostructual with monazite. An uncommon mineral, huttonite forms transparent or translucent cream–colored crystals. It was first identified in samples of ...