

It was named after its first locality (Danbury USA Connecticut 1839). Issues in pegmatites, hydrothermal ore veins and skarns. Its crystals usually has a typical wedge or chisel shape, it may be confused with topaz which has similar looking crystals but among others it has different hardness and cleavage. Largest localities: Mexico (San Luis Potosi), USA, Japan, Bolivia, Mianmar, Russia, Madagascar.