Emmonsite, also known as durdenite, is an

iron Iron is a chemical element; it has symbol Fe () and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, forming much of Earth's o ...

tellurite Tellurite is a oxyanion of tellurium with the formula . It is the ion of tellurous acid, and is chemically related to tellurium dioxide (), whose mineral appearance also bears the name tellurite. Tellurites are typically colorless or white salt ...

mineral with the formula: Fe₂(TeO₃)₃·2(H₂O). Emmonsite forms

triclinic class=skin-invert-image, 180px, Triclinic (a ≠ b ≠ c ≠ a and α, β, γ, 90° pairwise different) In crystallography, the triclinic (or anorthic) crystal system is one of the seven crystal systems. A crystal system is described by three b ...

crystals. It is of a yellowish-green color, with a vitreous luster, and a hardness of 5 on the Moh scale. Emmonsite-155152

Emmonsite was first described in 1885 for an occurrence in the Tombstone District,

Cochise County Cochise County ( ) is a county in the southeastern corner of the U.S. state of Arizona. It is named after Cochise, a Chiricahua Apache who was a key war leader during the Apache Wars. The population was 125,447 at the 2020 census. The county ...

, Arizona. It was named for the American geologist, Samuel Franklin Emmons, (1841–1911), of the

United States Geological Survey The United States Geological Survey (USGS), founded as the Geological Survey, is an agency of the U.S. Department of the Interior whose work spans the disciplines of biology, geography, geology, and hydrology. The agency was founded on Mar ...

. Emmonsite is found, often with

quartz Quartz is a hard, crystalline mineral composed of silica (silicon dioxide). The Atom, atoms are linked in a continuous framework of SiO4 silicon–oxygen Tetrahedral molecular geometry, tetrahedra, with each oxygen being shared between two tet ...

cerussite Cerussite (also known as lead carbonate or white lead ore) is a mineral consisting of lead carbonate with the chemical formula PbCO3, and is an important ore of lead. The name is from the Latin ''cerussa'', white lead. ''Cerussa nativa'' was ...

in the

Tombstone A gravestone or tombstone is a marker, usually stone, that is placed over a grave. A marker set at the head of the grave may be called a headstone. An especially old or elaborate stone slab may be called a funeral stele, stela, or slab. The us ...

, Arizona area. It is also associated with native tellurium,

, native gold,

pyrite The mineral pyrite ( ), or iron pyrite, also known as fool's gold, is an iron sulfide with the chemical formula Fe S2 (iron (II) disulfide). Pyrite is the most abundant sulfide mineral. Pyrite's metallic luster and pale brass-yellow hue ...

, rodalquilarite, mackayite, sonoraite, cuzticite and eztlite.

References

*Frost, Ray L. and Dickfos, Marilla J. and Keeffe, Eloise C. (2008) "Raman spectroscopic study of the tellurite minerals: emmonsite Fe23+Te34+O9.2H2O and zemannite Mg0.5 n2+Fe3+(TeO3)3.5H2O." ''Journal of Raman Spectroscopy'', 39(12). pp. 1784–1788. Found a
Queensland University of Technology website
Accessed September 15, 2010. *W. F. Hillebrand, "Emmonsite (?) from a new locality," American Journal of Science, Series 4 Vol. 18, December 1904, P.433-434; . Found a
AJS Online
Accessed September 15, 2010. Iron(III) minerals Tellurite minerals Triclinic minerals Minerals in space group 2 {{mineral-stub