Sulphur (Sulfur), also known as Brimstone, may be found within pumice, is a yellow, sulphur-yellow, brownish, greenish yellow, orange, or white color with a resinous, greasy luster. It is an extremely soft material with a hardness of 1½ - 2½.

It is typically found as a powdery yellow coating in sedimentary rocks, where large deposits are formed by reduction of sulfates. Sulphur is a common sublimate from volcanic gases associated with realgar, cinnabar and other minerals. It is also found in some vein deposits.

It has a low melting point of 113°C/235 °F, burns easily in air, with a low blue flame, and gives off choking fumes of sulphur-dioxide with an acrid odor (forms sulfurous and eventually sulfuric acid in air). Some of it's most common uses includes making fireworks, matches, and rubber.