Panethite
Encyclopedia
Panethite2(Mg,Fe)2(PO4)2 is a rare phosphate mineral that was only found in one meteorite
on Earth. It was originally found in the Dayton meteorite in Ohio
. It is classified as H-M Symbol (2/m) with space group of P 21/n. It is amber in color. It was named in the honor of Friedrich Adolf Paneth, a German chemist who made many contributions toward the discovery of the origin of the universe, and especially studies of meteorites.
and some disorder in the grains examined. Panethite has a monoclinic crystal system
with a0=10.18 +-0.01Å, b0=14.90 +-0.02Å, c0=25.87+-0.03Å and β =91.1˚, and its space group P21/n. Within the error that accompanied the microprobe analysis, the X-ray density was found to be 2.99g/ml.
and panethite were clear and transparent with no crystal faces; and neither present any discernible cleavage. Panethite is a biaxial negative, pale amber in its color and the estimated 2V was approximated to be 51˚. The refractive indices are α=1.567, β=1.576, γ = 1.579 all +-0.001 (Fuchs, 1716). Even though panethite lacks the lamellar structure that brianite shows, panethite shows simple twinning. The higher refractive indices along with the lamellae structure of brianite help us to distinguish these two minerals apart under the microscope. The specific gravity
of panethite was between 2.90 to 3.0. Both minerals were insoluble in water. Panethite and brianite are the minerals known to have the greatest amount of sodium content in meteorites (Fuchs, 1716).
Panethite was named after the director of the Max Planck Institute, Mainz
, Germany
, Friedrich Adolf Paneth (1887-1958).
Meteorite
A meteorite is a natural object originating in outer space that survives impact with the Earth's surface. Meteorites can be big or small. Most meteorites derive from small astronomical objects called meteoroids, but they are also sometimes produced by impacts of asteroids...
on Earth. It was originally found in the Dayton meteorite in Ohio
Ohio
Ohio is a Midwestern state in the United States. The 34th largest state by area in the U.S.,it is the 7th‑most populous with over 11.5 million residents, containing several major American cities and seven metropolitan areas with populations of 500,000 or more.The state's capital is Columbus...
. It is classified as H-M Symbol (2/m) with space group of P 21/n. It is amber in color. It was named in the honor of Friedrich Adolf Paneth, a German chemist who made many contributions toward the discovery of the origin of the universe, and especially studies of meteorites.
Structure
Using X-ray diffraction, the unit cell and the space group parameters were determined. The strongest lines of the X-ray were 5.10(6), 3.236(5), 3.007(10), 2.749, 2.710(7) (American Mineralogist, 509). But the error of the cell lengths were relatively high due to twinningCrystal twinning
Crystal twinning occurs when two separate crystals share some of the same crystal lattice points in a symmetrical manner. The result is an intergrowth of two separate crystals in a variety of specific configurations. A twin boundary or composition surface separates the two crystals....
and some disorder in the grains examined. Panethite has a monoclinic crystal system
Crystal system
In crystallography, the terms crystal system, crystal family, and lattice system each refer to one of several classes of space groups, lattices, point groups, or crystals...
with a0=10.18 +-0.01Å, b0=14.90 +-0.02Å, c0=25.87+-0.03Å and β =91.1˚, and its space group P21/n. Within the error that accompanied the microprobe analysis, the X-ray density was found to be 2.99g/ml.
Properties
Both brianiteBrianite
Brianite is a phosphate mineral with the chemical formula Na2CaMg2. It was first identified in an iron meteorite. This mineral is named after Brian Harold Mason, a pioneer in meteoritics....
and panethite were clear and transparent with no crystal faces; and neither present any discernible cleavage. Panethite is a biaxial negative, pale amber in its color and the estimated 2V was approximated to be 51˚. The refractive indices are α=1.567, β=1.576, γ = 1.579 all +-0.001 (Fuchs, 1716). Even though panethite lacks the lamellar structure that brianite shows, panethite shows simple twinning. The higher refractive indices along with the lamellae structure of brianite help us to distinguish these two minerals apart under the microscope. The specific gravity
Specific gravity
Specific gravity is the ratio of the density of a substance to the density of a reference substance. Apparent specific gravity is the ratio of the weight of a volume of the substance to the weight of an equal volume of the reference substance. The reference substance is nearly always water for...
of panethite was between 2.90 to 3.0. Both minerals were insoluble in water. Panethite and brianite are the minerals known to have the greatest amount of sodium content in meteorites (Fuchs, 1716).
Panethite was named after the director of the Max Planck Institute, Mainz
Mainz
Mainz under the Holy Roman Empire, and previously was a Roman fort city which commanded the west bank of the Rhine and formed part of the northernmost frontier of the Roman Empire...
, Germany
Germany
Germany , officially the Federal Republic of Germany , is a federal parliamentary republic in Europe. The country consists of 16 states while the capital and largest city is Berlin. Germany covers an area of 357,021 km2 and has a largely temperate seasonal climate...
, Friedrich Adolf Paneth (1887-1958).