How do I identify Simmonsite?

Simmonsite can be identified by its hardness of 2.5 - 3 on the Mohs scale, Cloudy white color. Look for these key characteristics when examining specimens.

What color is Simmonsite?

Simmonsite typically appears in Cloudy white, Cream white, pale buff. Color can vary depending on impurities and formation conditions.

How hard is Simmonsite?

Simmonsite has a hardness of 2.5 - 3 on the Mohs scale. This makes it a soft mineral that can be scratched easily.

Simmonsite

A variety of Minerals

What is Simmonsite?

Simmonsite is a halide mineral, being a tertiary light metal fluoride, with formula Na2LiAlF6. It was first discovered in nature in Mineral County in the Gillis Range of Nevada, U.S.A. The mineral is found intergrown with cryolite, cryolithionite and trace elpasolite. The mineral has a monoclinic structure of P2 or P2/m. The ideal chemical formula for simmonsite is Na2LiAlF6. The mineral has a no visible cleavage, Mohs hardness of 2.53, a pale white color with a white streak and feels somewhat greasy. Simmonsite was named for the Professor of Mineralogy and Petrology at the University of New Orleans, William B. Simmons.

Simmonsite Market Value Calculator

Estimate the market value of Simmonsite using size, quality, and finish. This preview calculator is for quick context and is not a formal appraisal.

Simmonsite Localities Map

See where Simmonsite is found with a localities map, collecting zones, and geology context. Generate a sample map preview below.

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North ZoneCentral RidgeSouth Basin

Key Characteristics

Characteristics of Simmonsite

Simmonsite contains no observable euhedral crystals but it does have complex polysynthetic twinning. Its color is pale buff to cream in the hadn specimens accompanied by a white streak and has a greasy appearance. It exhibits a hardness of 2.5-3 on the Mohs hardness scale. There is no apparent cleavage, a subconchoidal fracture, no parting, and is not brittle. The measured density is 3.05(2) g/cm.

Formation of Simmonsite

Simmonsite, cryolite and cryolithionite form together as part of the alumino-fluoride aassemblage in a late stage breccia pipe structure that cross the Zapot amazonite-topaz-zinnwaldite pegmatite located in the described location above in Nevada. This assemblage occurs with around a third of each of theses phases. The three phases form an intergrowth of anhedral to subhedral grains that can be micrometers to approximately two or three hundred micrometers in size. The main anhydrous alumino-fluorides results in size almost 20cm or more across and weight more than 1kg. Another assemblage of alumino-fluorides exist, some that contain water or hydroxyl, pachnolite, weberite, thomsenollite, prosopite, ralstonite, as well as a second generation of cryolithionite.