Boiling point 717.75 Stable isotopes 4 Heat of vapor. Sulfur Ordinary sulfur is a yellow solid substance which forms crystals with orthorhombic symmetry. It is insoluble in water, but can be dissolved in carbon disulfide, carbon tetrachloride, and similar non-polar solvents. As the liquid is heated, it gradually darkens in color and becomes more viscous.
Most substances decrease in viscosity with increasing temperature.
Sulfur is unique in that it forms long chain molecules with increasing temperature, called gamma sulfur. Reference Pauling Ch. Spin Natural Abund.