Mosesite is a very rare
mineral
In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid chemical compound with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form.John P. Rafferty, ed. ...
found in few locations. It is a
mercury
Mercury commonly refers to:
* Mercury (planet), the nearest planet to the Sun
* Mercury (element), a metallic chemical element with the symbol Hg
* Mercury (mythology), a Roman god
Mercury or The Mercury may also refer to:
Companies
* Mercur ...
mineral found as an accessory in deposits of mercury, often in conjunction with
limestone
Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms wh ...
. It is known to be found in the
U.S. state
In the United States, a state is a constituent political entity, of which there are 50. Bound together in a political union, each state holds governmental jurisdiction over a separate and defined geographic territory where it shares its sove ...
s of
Texas
Texas (, ; Spanish language, Spanish: ''Texas'', ''Tejas'') is a state in the South Central United States, South Central region of the United States. At 268,596 square miles (695,662 km2), and with more than 29.1 million residents in 2 ...
and
Nevada
Nevada ( ; ) is a state in the Western region of the United States. It is bordered by Oregon to the northwest, Idaho to the northeast, California to the west, Arizona to the southeast, and Utah to the east. Nevada is the 7th-most extensive, ...
, and the
Mexican state
The states of Mexico are first-level administrative territorial entities of the country of Mexico, which is officially named United Mexican States. There are 32 federal entities in Mexico (31 states and the capital, Mexico City, as a separate ent ...
s of
Guerrero
Guerrero is one of the 32 states that comprise the Administrative divisions of Mexico, 32 Federal Entities of Mexico. It is divided in Municipalities of Guerrero, 81 municipalities and its capital city is Chilpancingo and its largest city is Acap ...
and
Querétaro
Querétaro (), officially the Free and Sovereign State of Querétaro ( es, Estado Libre y Soberano de Querétaro, links=no; Otomi: ''Hyodi Ndämxei''), is one of the 32 federal entities of Mexico. It is divided into 18 municipalities. Its capi ...
. It was named after Professor
Alfred J. Moses
Alfred may refer to:
Arts and entertainment
*''Alfred J. Kwak'', Dutch-German-Japanese anime television series
* ''Alfred'' (Arne opera), a 1740 masque by Thomas Arne
* ''Alfred'' (Dvořák), an 1870 opera by Antonín Dvořák
*"Alfred (Interlu ...
(1859–1920) for his contributions to the field of
mineralogy
Mineralogy is a subject of geology specializing in the scientific study of the chemistry, crystal structure, and physical (including optical) properties of minerals and mineralized artifacts. Specific studies within mineralogy include the proce ...
in discovering several minerals found alongside mosesite. The mineral itself is various shades of yellow and a high occurrence of
spinel
Spinel () is the magnesium/aluminium member of the larger spinel group of minerals. It has the formula in the cubic crystal system. Its name comes from the Latin word , which means ''spine'' in reference to its pointed crystals.
Properties
...
twinning. It becomes
isotropic when heated to .
Composition
Mosesite contains 16 Hg, 3 Cl, SO
4, CO
3, MoO
4, 16 H, and 8 N with a volume of 8.4777x10
−1 nm
3 and calculated density of 7.53 g/cm
3. Its chemical formula is .
Geologic occurrence
Discovered in a mercury mine in
Terlingua, Texas
Terlingua ( ) is a mining district and census-designated place (CDP) in southwestern Brewster County, Texas, United States. It is located near the Rio Grande and the villages of Lajitas and Study Butte, Texas, as well as the Mexican state o ...
, mosesite has also been seen in Nevada and Mexico. Mosesite is a secondary mineral formed at low temperature in hydrothermal mercury deposits. The mercury ore at the mine in
Huahuaxtla is aligned with ribs of
breccia
Breccia () is a rock composed of large angular broken fragments of minerals or rocks cemented together by a fine-grained matrix.
The word has its origins in the Italian language, in which it means "rubble". A breccia may have a variety of d ...
ted
limestone
Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms wh ...
that formed along a shallow-angle
fault plane. In the Huahuaxtla mine, this is due to the evidence of oxidized minerals. The portion of the mine in which the mosesite was found is thought to be a solution cavity in a zone of fractured limestone. Mosesite is never found in abundance in any of the known locations of its origin. Mineral associations include
montroydite
Montroydite is the mineral form of mercury(II) oxide with formula HgO. It is a rare mercury mineral. It was first described for an occurrence in the mercury deposit at Terlingua, Texas and named for Montroyd Sharp who was an owner of the deposit.
...
,
calcite
Calcite is a carbonate mineral and the most stable polymorph of calcium carbonate (CaCO3). It is a very common mineral, particularly as a component of limestone. Calcite defines hardness 3 on the Mohs scale of mineral hardness, based on scra ...
,
gypsum
Gypsum is a soft sulfate mineral composed of calcium sulfate dihydrate, with the chemical formula . It is widely mined and is used as a fertilizer and as the main constituent in many forms of plaster, blackboard or sidewalk chalk, and dr ...
, and at some localities native
mercury
Mercury commonly refers to:
* Mercury (planet), the nearest planet to the Sun
* Mercury (element), a metallic chemical element with the symbol Hg
* Mercury (mythology), a Roman god
Mercury or The Mercury may also refer to:
Companies
* Mercur ...
.
Structure
Spinel
Spinel () is the magnesium/aluminium member of the larger spinel group of minerals. It has the formula in the cubic crystal system. Its name comes from the Latin word , which means ''spine'' in reference to its pointed crystals.
Properties
...
twinning is a common occurrence in mosesite. Mosesite was found to have a
unit cell
In geometry, biology, mineralogy and solid state physics, a unit cell is a repeating unit formed by the vectors spanning the points of a lattice. Despite its suggestive name, the unit cell (unlike a unit vector, for example) does not necessari ...
with diamond type space lattice and the measured
unit cube
A unit cube, more formally a cube of side 1, is a cube whose sides are 1 unit long.. See in particulap. 671. The volume of a 3-dimensional unit cube is 1 cubic unit, and its total surface area is 6 square units..
Unit hypercube
The term '' ...
of Mosesite was approximately 9.44 nmx10
−1 with additional forms , , , , and . In Mexico, the mosesite was most usually found as octahedral crystals which were usually intergrown. Single crystals are rare. Mosesite has a similar structure to
Millon’s base (Hg
2NOH•''n''H
20). Mosesite consists of a three-dimensional framework of Hg
2N
+ groups. The mercury atoms form linear sp bonds, while the nitrogen forms tetrahedral sp3 bonds, in a
face-centered cubic
In crystallography, the cubic (or isometric) crystal system is a crystal system where the unit cell is in the shape of a cube. This is one of the most common and simplest shapes found in crystals and minerals.
There are three main varieties o ...
lattice. The
space group
In mathematics, physics and chemistry, a space group is the symmetry group of an object in space, usually in three dimensions. The elements of a space group (its symmetry operations) are the rigid transformations of an object that leave it ...
of mosesite is F*43m.
Physical properties
Mosesite is a minute yellow crystal with imperfect
cleavage
Cleavage may refer to:
Science
* Cleavage (crystal), in mineralogy and materials science, a process of splitting a crystal
* Cleavage (geology), the foliation perpendicular to stress as a result of ductile deformation
* Cleavage (embryo), in emb ...
along and uneven fracture. It is brittle with a hardness of 3.5. Long exposure, a month or more, to light will change Mosesite to a light olive green color. The powdered form retains its color streaking a light yellow. The mineral exhibits no
pleochroism
Pleochroism (from Greek πλέων, ''pléōn'', "more" and χρῶμα, ''khrôma'', "color") is an optical phenomenon in which a substance has different colors when observed at different angles, especially with polarized light.
Backgrou ...
and displays uneven
birefringence
Birefringence is the optical property of a material having a refractive index that depends on the polarization and propagation direction of light. These optically anisotropic materials are said to be birefringent (or birefractive). The birefrin ...
in polarized light. Heat has a notable effect on Mosesite for when heated above the mineral becomes isotropic. This corresponds optically with the observed crystal form only at this higher temperature. It is considered weakly anisotropic. The index of refraction is ''n'' = 2.065±0.01. It has an adamantine luster that officially ranges in color from lemon yellow to canary yellow. Mosesite reacts chemically with HCl leaving a residue of HgCl.
References
* Bird, 1932 Paul H. Bird, A New Occurrence and X-ray Study of Mosesite, American Mineralogist 17 (12) (1932), pp. 541–550.
* Canfield et al. 1910 F.A. Canfield, W.F. Hillebrand, W.T. Schaller, Mosesite, a New Mercury Mineral from Terlingua, Texas,
American Journal of Science
The ''American Journal of Science'' (''AJS'') is the United States of America's longest-running scientific journal, having been published continuously since its conception in 1818 by Professor Benjamin Silliman, who edited and financed it himsel ...
30 (1910), pp. 202–208.
* Luquer, 1920 Lea McI. Luquer, Alfred J. Moses, American Mineralogist 5 (6) (1920), pp. 109–112.
* Switzer et al., 1953 George S. Switzer, W.F. Foshag, K.J. Murata, J.J. Fahey, Re-Examination of Mosesite, American Mineralogist 38 (11-12), pp. 1225–1234.
{{Ref end
Bibliography
*
Palache, P.; Berman H.; Frondel, C. (1960). "''Dana's System of Mineralogy, Volume II: Halides, Nitrates, Borates, Carbonates, Sulfates, Phosphates, Arsenates, Tungstates, Molybdates, Etc. (Seventh Edition)"'' John Wiley and Sons, Inc., New York, pp. 89-90.
Mercury minerals
Cubic minerals
Minerals in space group 216