Although only small amounts of H 2 S form from just moisture in the air, it is a powerful odor producer and is the dominating contributor to the odor of rotten eggs. Rest assured, though, that most specimens of sulfur, when kept dry, do not emit a strong odor and this is not difficult for collectors of fine sulfur specimens to ensure. Color is a strong yellow color in thick crystals and duller yellow in small crystals to pale yellow in massive or powdery forms. Can also be reddish or greenish yellow with impurities. Luster is vitreous to more often resinous or earthy in massive forms.
Transparency is transparent to translucent.
Crystal Habits include mostly massive or powdery forms but well shaped blocky crystals are common. Cleavage is very poor in two directions. Fracture is conchoidal. Streak is yellow. Hardness is 2.