The Mineral sulfur

Classic Sulfur Crystal

Pure Sulfur is bright yellow. The color may be altered if impurities are present. Clay and selenium impurities, as well as volcanic mixtures in sulfur can cause it to be slightly red, green, brown, or gray. Sulfur often occurs in petroleum deposits, where it is found coated with greasy black petroleum.

Sulfur is soft, light in weight, and very brittle. Care must be exercised when handling and storing specimens. When kept moist or not allowed to dry when wet, hydrogen will mix with the Sulfur, forming hydrogen sulfide (H2S), which causes the deterioration of a specimen. To prevent this, Sulfur should not be stored under humid conditions. It is best not to wash Sulfur specimens, as warm water can dissolve them. Sulfur also has the tendency to crack when exposed to mild heat, including body heat. It should be handled as little as possible, and kept out of light to avoid cracking.

The earthy, massive, specimens usually come from volcanic sulfur springs, and have small, bubbly holes throughout. These specimens usually have a greasy feel, and exhibit a strong "rotten-egg" odor.

Much of the fine natural Sulfur crystals are destroyed by mining operations. In mining, underground Sulfur deposits are flooded with hot water, causing the Sulfur to melt into a brine. The brine is pumped to the surface, where the water is evaporated and the sulfur recovered. Such mining operations destroy all specimens.

Sulfur crystallizes in the orthorhombic system, but an uncommon monoclinic form of sulfur also exists. This monoclinic form is scientifically considered a different mineral than Sulfur, and is scientific name is Rosickyite.

Chemical Formula



Bright yellow to yellow-brown

Crystal System



1.5 - 2.5
Transparent to opaque
Specific Gravity
2.0 - 2.1
Adamantine on clean, clear crystal surfaces; otherwise resinous or dull
Other ID Marks
1) Cracks when exposed to heat
2) Dissolves in warm water
3) May have a greasy feel
4) Gives off a mild, sulfuric odor. Odor becomes strong if heated.

Crystal Habits

Steep dipyramidal and tabular crystals are common. May also be bipyramidal with angled centers. Crystals frequently have hollow skeletons or  hoppered growths. Curved and rounded distorted crystals are also common. Small grains, wheat sheaves, and encrustings occur. Massive, earthy specimens are prevalent, and may have bubbly holes throughout. Also occurs as rounded, waterworn masses.

3D Crystal Atlas

Additional Information

In Group
Native Elements; Non-Metallic Elements
Striking Features
Color, softness, very low density, and habit of cracking when exposed to heat.
In sedimentary environments in evaporite and salt dome deposits, where it often is a product of breakdown of sulfates caused by cetain bacteria. In volcanic deposits in hot springs and fumaroles as a product of sublimation. Also occurs in igneous basalt rocks of recent volcanic activity.
Rock Type
Igneous, Sedimentary

Other Names

Native Sulfur
Native Sulphur
Sulphur Synonym of Sulfur. This spelling variant is used in Great Britian and other English-speaking locations outside the United States.


 -   Uncommon polymorph of Sulfur. Rosikyite crystallizes in the monoclinic system, whereas Sulfur crystallizes in the orthorhombic system. Other than that, they share the same properties. Since Rosickyite and Sulfur crystallize differently, they are scientifically classified as separate minerals.


Sulfur is a common element, with many uses. Although most sulfur is extracted from sulfides, Native Sulfur, being common, is also used as a source. The fine specimens from Agrigento and Cattolico in Sicily, Italy, are highly sought by mineral collectors and command very high prices.

Sulfur has many industrial uses. It is used in the manufacture of black powder, matches and explosives. It is also used to create rubber, in dyes, and as an insecticide and fungicide. It is also used in the manufacturing of sulfuric acid.

Noteworthy Localities

The most famous and classic Sulfur specimens have come from the Italian mines on the island of Sicily. These localities have produced well crystallized and brightly colored gemmy yellow crystals that are highly sought after. Important Sicilian deposits include Agrigento (Girgenti), the Cozzodisi Mine (Casteltermini), Cianciana, and Cattolico. Another outstanding Italian locality is the Perticara Mine, Pesaro-Urbino Province, on the Italian mainland.

The Conil Mine in Cadiz Province, Andalusia, Spain, is an historical European locality that had once produced exceptional Sulfur crystals. Two other classic European localities are the Machów mine, Tarnobrzeg, Poland; and the Vodinskoye Deposit, Samarskaya Russia.

Bolivia has recently been producing an unending source of fabulous Sulfur specimens from the remote El Desierto mine in Potosí Department. Specimens include crystal plates on a crumbly matrix as well as some fairly large sized crystals. A well-known Mexican occurrence is San Felipe, in Baja California Norte.

In the U.S. fine Sulfur specimens have been found at Maybee, Monroe Co., Michigan; Steamboat Springs, Washoe Co., Nevada; and at Yellowstone National Park, Wyoming. The salt domes of Texas and Louisiana also contain vast Sulfur deposits, but the industrial mining methods destroys all crystals. A few drill cores from mining operations deep into the earth have in Texas and Louisiana have been found with fine Sulfur crystals on them, indicating that indeed excellent crystals within the earth are all but destroyed by the mining operations.

Common Mineral Associations

Aragonite, Barite, Celestine, Gypsum, Calcite, Realgar, Cinnabar

Distingushing Similar Minerals

Due to its unique properties, Sulfur is easily distinguishable from all minerals.


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