Number of allotropes of sulphur explain

Sulphur forms numerous allotropes, but let us study the two most important allotropes of sulphur-

yellow rhombic sulphur (α-sulphur) and the monoclinic (β-sulphur). The most interesting feature is their thermal stability, the allotropes of sulphur are inter-convertible i.e. rhombic sulphur when heated above 369K gives monoclinic sulphur. 

Rhombic sulphur (α-sulphur)

Rhombic sulphur is crystalline in nature and has octahedral shape. On heating the solution of roll sulphur in CS2 we get rhombic sulphur. It is yellow with a melting point of 385.8K and specific gravity 2.06. Rhombic sulphur cannot be dissolved in water but can be dissolved in benzene, ether, alcohol etc.

Monoclinic sulphur (β-sulphur)

When we take a dish and melt rhombic sulphur in that dish we obtain monoclinic sulphur after cooling it. In this process we make two holes in the crust and pour out the remaining liquid. After this we get colourless needle-shaped crystals of β-sulphur when the crust is removed.