14 Mart 2013 Perşembe

Louisiana State Mineral

Louisiana State Mineral


Sulfur, also spelled sulphur, is found as the pure element native sulfur and is also extracted from sulfate and sulfide minerals. It occurs in blocky dipyramids, so named because they form two symmetrical crystals attached on a single plane. Normally a bright yellow to yellowish-brown mineral, sulfur is quite soft, only 1.5–2.5 on the Mohs hardness scale, and often forms a powdery yellowish coating. Sulfur can also be greenish yellow, orange, or white. Sulfur dissolves in warm water and often has a greasy feel, but its most distinguishing characteristic is its sulfuric, "rotten egg" smell when sulfur mixes with water and forms small amounts of hydrogen sulfide. The odor becomes stronger with heat.
The city of Sulphur, Louisiana, was named for the industry that helped establish Calcasieu Parish in the late 1800s. Although all current sulfur production in Louisiana comes from a mine that is 27 kilometers offshore, sulfur is the state’s second-leading mineral commodity. Freeport-McMoRan Sulphur Inc., the company that operates the mine, is based in New Orleans. The company mines the sulfur using the Frasch process, in which steam is injected into the ground until the sulfur is molten. Louisiana does not have an official state mineral, but sulfur is important to the state’s economy, history, and geology.
The words sulfur and sulphur come from the Middle English wordsulphur and the Latin word sulphurium, which means "burning stone." This is a reference to the element’s formation in volcanic regions and its low melting point. Brimstone is an ancient name for sulfur.
Sulfur is normally formed by volcanic action. Volcanic regions, such as along the Pacific Ring of Fire, and sulfuric hot springs produce crumbly, massive specimens of elemental sulfur, as well as a strong sulfuric smell. Sulfur is also found in some vein deposits, in sedimentary rocks, and in salt domes along the United States Gulf Coast. The element is associated with gypsum, halite, calcite, anhydrite, realgar, cinnabar, celestine, and barite. Much sulfur is produced as by-products of the oil and natural gas industries.
Numerous localities for sulfur are known, but some occurrences are inconspicuous. Localities for the best specimens are listed here.
  • USA: salt domes near Lake Charles, Calcasieu Parish, Louisiana; salt domes near Freeport, Brazoria County, Texas; Sulfur Mountain, in Yellowstone Park, Wyoming; Sulfur Bank mercury mine, on Clear Creek, Lake County, California; quarries at Maybee and Scofield, Monroe County, Michigan
  • Italy: Cianciana, Agrigento, and Racalmuto, Sicily; Solfatara di Pozzuoli, near Naples; at Perticara, near Rimini, Marche; and at Carrara, Tuscany
  • Spain: Conil, near Cádiz, Cádiz Province
  • Mexico: San Felipe, Baja California
Sulfur is a micronutrient, which means it is essential for human and animal health, and is found in the amino acids cysteine and methionine. Native sulfur is common, and the element is also extracted from sulfide minerals. Sulfur is used to manufacture black powder, matches, explosives, rubber, and sulfuric acid. Sulfuric acid has many industrial and chemical applications. Sulfur is used to make dyes, fungicides, and insecticides.
Mineral collectors appreciate sulfur for its attractive specimens with bright yellow, well-formed crystals. Some of the most famous, most beautiful, and most highly sought-after specimens come from several mines on Sicily, Italy.
State Mineral
Sulfur Sample
State Mineral
Sulfur Crystals
State Mineral
Sulfur Crystals in Rock
State Mineral
Sulfur Matches
Group: Element (nonmetal)
Chemical Formula: S
Crystal Structure: Orthorhombic
Hardness (Mohs): 1½-2½
Color: Yellow, sulphur-yellow, brownish or greenish yellow, orange, white
Transparency: Transparent, translucent
Luster: Resinous, greasy
Density: 2.07 g/cm3
Streak: Colorless
Cleavage: Imperfect/fair
Imperfect on {001}, {110} and {111}.
Fracture: Irregular/uneven, conchoidal
Tenacity: Brittle

Some data courtesy of the Mineralogical Society of America
Author: World Trade Press

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