Mosesite
Encyclopedia
Mosesite is a very rare mineral found in few locations. It is a mercury
mineral found as an accessory in deposits of mercury, often in conjunction with limestone
. It is known to be found in the U.S. state
s of Texas
and Nevada
, and the Mexican states of Guerrero
and Querétaro
. It was named after Professor Alfred J. Moses for his contributions to the field of mineralogy
in discovering several minerals found alongside mosesite. The mineral itself is various shades of yellow and a high occurrence of spinel
twinning. It becomes isotropic when heated to 186 °C (366.8 °F).
, 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
ted limestone
that formed along 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.
twinning is a common occurrence in mosesite. Mosesite was found to have a unit cell with diamond type space lattice and the measured unit cube
of Mosesite was approximately 9.44 nmx10−1 with additional forms {001}, {011}, {116}, {114}, and {112}. 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 (Hg2NOH•nH20). Mosesite consists of a three-dimensional framework of Hg3N+ groups. The mercury atoms form linear sp bonds, while the nitrogen forms tetrahedral sp3 bonds, in a face-centered cubic
lattice. The space group
of mosesite is F*43m.
along {111} 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. The powdered form retains its color streaking a light yellow. The mineral exhibits no pleochroism
and displays uneven birefringence
in polarized light. Heat has a notable effect on Mosesite for when heated above 186 °C (366.8 °F) 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 officially ranges in color from lemon yellow to canary yellow. Mosesite reacts chemically with HCl leaving a residue of HgCl.
Mercury (element)
Mercury is a chemical element with the symbol Hg and atomic number 80. It is also known as quicksilver or hydrargyrum...
mineral found as an accessory in deposits of mercury, often in conjunction with limestone
Limestone
Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera....
. It is known to be found in the U.S. state
U.S. state
A U.S. state is any one of the 50 federated states of the United States of America that share sovereignty with the federal government. Because of this shared sovereignty, an American is a citizen both of the federal entity and of his or her state of domicile. Four states use the official title of...
s of Texas
Texas
Texas is the second largest U.S. state by both area and population, and the largest state by area in the contiguous United States.The name, based on the Caddo word "Tejas" meaning "friends" or "allies", was applied by the Spanish to the Caddo themselves and to the region of their settlement in...
and Nevada
Nevada
Nevada is a state in the western, mountain west, and southwestern regions of the United States. With an area of and a population of about 2.7 million, it is the 7th-largest and 35th-most populous state. Over two-thirds of Nevada's people live in the Las Vegas metropolitan area, which contains its...
, and the Mexican states of Guerrero
Guerrero
Guerrero officially Estado Libre y Soberano de Guerrero is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is divided in 81 municipalities and its capital city is Chilpancingo....
and Querétaro
Querétaro
Querétaro officially Estado Libre y Soberano de Querétaro de Arteaga is one of the 31 states which, with the Federal District, comprise the 32 Federal Entities of Mexico. It is divided into 18 municipalities and its capital city is Santiago de Querétaro....
. It was named after Professor Alfred J. Moses for his contributions to the field of mineralogy
Mineralogy
Mineralogy is the study of chemistry, crystal structure, and physical properties of minerals. Specific studies within mineralogy include the processes of mineral origin and formation, classification of minerals, their geographical distribution, as well as their utilization.-History:Early writing...
in discovering several minerals found alongside mosesite. The mineral itself is various shades of yellow and a high occurrence of spinel
Spinel
Spinel is the magnesium aluminium member of the larger spinel group of minerals. It has the formula MgAl2O4. Balas ruby is an old name for a rose-tinted variety.-Spinel group:...
twinning. It becomes isotropic when heated to 186 °C (366.8 °F).
Composition
Mosesite contains 16 Hg, 3 Cl, 1½ SO4, ½ CO3 , ½ MoO4, 16 H, and 8 N with a volume of 8.4777x10−1 nm³ and calculated density of 7.53 g/cm³. The accepted formula for mosesite is Hg2N(Cl,SO4,MoO4,CO3)•H20.Geologic occurrence
Discovered in a mercury mine in Terlingua, TexasTerlingua, Texas
Terlingua is a mining district in southwestern Brewster County, Texas, United States. It is located near the Rio Grande and the Texas villages of Lajitas and Study Butte, Texas,as well as the Mexican village of Santa Elena. The discovery of cinnabar, from which the metal mercury is extracted, in...
, 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
Breccia is a rock composed of broken fragments of minerals or rock cemented together by a fine-grained matrix, that can be either similar to or different from the composition of the fragments....
ted limestone
Limestone
Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera....
that formed along 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.
Structure
SpinelSpinel
Spinel is the magnesium aluminium member of the larger spinel group of minerals. It has the formula MgAl2O4. Balas ruby is an old name for a rose-tinted variety.-Spinel group:...
twinning is a common occurrence in mosesite. Mosesite was found to have a unit cell with diamond type space lattice and the measured unit cube
Unit cube
A unit cube, sometimes called a cube of side 1, is a cube whose sides are 1 unit long. The volume of a 3-dimensional unit cube is 1 cubic unit, and its total surface area is 6 square units.- Unit Hypercube :...
of Mosesite was approximately 9.44 nmx10−1 with additional forms {001}, {011}, {116}, {114}, and {112}. 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 (Hg2NOH•nH20). Mosesite consists of a three-dimensional framework of Hg3N+ groups. The mercury atoms form linear sp bonds, while the nitrogen forms tetrahedral sp3 bonds, in a face-centered cubic
Cubic crystal system
In crystallography, the cubic 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....
lattice. The space group
Space group
In mathematics and geometry, a space group is a symmetry group, usually for three dimensions, that divides space into discrete repeatable domains.In three dimensions, there are 219 unique types, or counted as 230 if chiral copies are considered distinct...
of mosesite is F*43m.
Physical properties
Mosesite is a minute yellow crystal with imperfect cleavageCleavage (crystal)
Cleavage, in mineralogy, is the tendency of crystalline materials to split along definite crystallographic structural planes. These planes of relative weakness are a result of the regular locations of atoms and ions in the crystal, which create smooth repeating surfaces that are visible both in the...
along {111} 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. The powdered form retains its color streaking a light yellow. The mineral exhibits no pleochroism
Pleochroism
Pleochroism is an optical phenomenon in which a substance appears to be different colors when observed at different angles with polarized light.- Background :Anisotropic crystals will have optical properties that vary with the direction of light...
and displays uneven birefringence
Birefringence
Birefringence, or double refraction, is the decomposition of a ray of light into two rays when it passes through certain anisotropic materials, such as crystals of calcite or boron nitride. The effect was first described by the Danish scientist Rasmus Bartholin in 1669, who saw it in calcite...
in polarized light. Heat has a notable effect on Mosesite for when heated above 186 °C (366.8 °F) 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 officially ranges in color from lemon yellow to canary yellow. Mosesite reacts chemically with HCl leaving a residue of HgCl.