A mineral sample has a mass of 5.94 g and a volume of 0.73 cm³. The mineral is either sphalerite (density = 4.0 g/cm³), cassiterite (density = 6.99 g/cm³), or cinnabar (density = 8.10 g/cm³). Which mineral is it?
a) Sphalerite
b) Cassiterite
c) Cinnabar
d) Insufficient information to determine.