Sulfur Composition, Crystallization, Structure and Occurrence

Composition. Sulfur; often impure with clay, bitumen, etc. 

Crystallization. Orthorhombic. Pyramidal in habit. Often with two pyramided, brachycome and base in combination.

Structure. Often in irregular masses imperfectly crystallized. Massive, reniform, stalactitic, as incrustations, earthy.

Physical Properties. H. = 1.5 – 2.5.   G = 2.05 – 2.09. Resinous luster. Color sulfur – yellow, varying with impurities to yellow shades of green, gray and red. Transparent to opaque. Imperfect conductor of heat. When a fragment is held in the hand close to the ear it will be heard to erack. This is due to the expansion of the surface layers because of the heat form the hand, while the interior, on account of the slow heat conductivity, is unaffected. Crystals of sulfur should, therefore, be handled with care.

Test. Fusible at 1 and burns with a blue flame giving strong odor of sulfur dioxide. Sublimes in C.T. giving a red to dark yellow liquid when hot, yellow solid when cold. Told by is yellow color and the ease which it burns.

Occurrence. Sulfur often occurs with active or extinct volcanoes where is has been derived from the gases given off in fumaroles. These may furnish sulfur as a direct sublimation product or by the incomplete oxidation of hydrogen sulphidegas. 

It is also formed by the reduction of sulfates, especially gypsum. At times it is deposited from sulfur – bearing waters by the action of the so-called sulfur bacteria. Sometimes in connection with sulfides in metallic veins and derived from their oxidation. It is most commonly found in the Tertiary sedimentary rocks and most frequently associated with gypsum and limestone; often in clay rocks; frequently with bituminous deposits. Found in large deposits an din fine crystals near Gigantic, Sicily, associated with celestite, gypsum, calcite, aragonite, etc.; also in connection with the volcanoes of Mexico, Hawaii, Japan, etc., In the United States the most productive deposits are in Louisiana and Texas. In Calcasieu Parish, Louisiana, a bed of sulfur 100 ft. thick is found at a depth of between 300 and 400 ft. it is associated with limestone, gypsum, anhydrite, and salt. Similar deposits occur at Freeport and at Gulf, Texas. Sulfur also occurs in Wyoming. Utah and California.

Use. Used in the manufacture of sulfuric acid, in the manufacture of matches, gunpowder, fretworks, insecticides, for vulcanizing rubber, in medicine and in the preparation of wood pulp for paper manufacture.