Arsenic is one of the semimetals/metalloids. It has a metallic luster and bright silvery gray color on freshly broken surfaces. Weathered, tarnished surfaces have a very dull metallic to nonmetallic luster and dark gray color. Arsenic has a gray streak, no cleavage, and is moderately soft (H = 3.5). Like all semimetals/metalloids, arsenic is not malleable - it breaks along fractures.
Arsenic (3.0 cm across) from Andreasberg, Harz Mountains, Germany.