There are three triple point :
- 1 (95.4 c 1× 10-4 latm) - rhombic s is inequilibrium with monoclinic s,and both have the same vapor pressure.
- 2 (119 c 5× 10-4 latm) - monoclinic s melt ; this is the triple point for Sm-Sl-Sg.
- 3 (151 c , 1288 atm ) - rhombic,monoclinic,and liquid S are at equilibrium.
The critical point - where liquid and gaseous s have the same density - is off to the right at 1041 c and 203.3 atm