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Abramovit and Absvürmbahit

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Abramovit is a rare mineral, sulfosol from the cylindrite group. Named in honor of Dmitry Vadimovich Abramov, Russian mineralogist. It was first discovered in the Far East, on the Kuril Islands.

Abramovit has black color, black color of the line, metallic luster, average hardness on the Mohs scale, perfect cleavage, density 7.64. The formula is Pb2SnInBiS7. The mineral is opaque.

Molecular Weight of 1,066.44
The origin of the name In honor of Dmitry Vadimovich Abramov (1963 -), Russian mineralogist, employee of the Mineralogical Museum named after A.E. Fersman, Russia.
IMA status approved 2006
CLASSIFICATION
Dana (8th Edition) 3.1.3.3
PHYSICAL PROPERTIES
Mineral color silver black
Stroke color black
Transparency opaque
Gloss metallic
Cleavage perfect for {100}
Density (measured) Bulk Density (Electron Density) = 7.64 gm / ccnote: Specific Gravity of Abramovite = 9.00 gm / cc.
Radioactivity (GRapi) 0
CRYSTALLOGRAPHIC PROPERTIES
Point group 1 - pinacoidal
Space group P1
Syngonia Triklinnaya
Cell parameters a = 23.4 (3) Å, b = 5.77 (2) Å, c = 5.83 (2) Å
α = 89.1 °, β = 89.9 °, γ = 91.5 °
Ratio a: b: c = 4.055: 1: 1.01
Unit cell volume V 786.79 ų (calculated by unit cell parameters)

Absvürmbahit is a rare mineral named after the German mineralogist who discovered it. It has a saturated black color, tetragonal syngony, the formula CuMn6O8 (SiO4), a black stroke color, density 4.96, and also a fairly high hardness on the Mohs scale. Opaque. Cleavage in abswurmbachite is absent. The main impurities are Ti, Al, Fe, Cu, Mg, Ca.

CLASSIFICATION
Strunz (8th Edition) 8 / B.09-05
Strunz (9th edition) 9.AG.05
Dana (8th Edition) 7.5.1.4
Hey's CIM Ref. 14.18.6
PHYSICAL PROPERTIES
Mineral color black
The color is brownish black.
Transparency opaque
Gloss metallic
Cleavage no
Hardness (Mohs scale) 6.5
Density (measured) 4.96
Density (estimated) 4.96 g / cm3
Radioactivity (GRapi) 0
CRYSTALLOGRAPHIC PROPERTIES
Dot group 4 / mmm (4 / m 2 / m 2 / m) - Di Tetragonal Dipyramidal
Space group I41 / acd (I41 / a 2 / c 2 / d)
Syngonia Tetragonal
Cell parameters a = 9.406Å, c = 18.546Å
Ratio a: c = 1: 1.972
The number of formula units (Z) 8
Unit cell volume V 1640.82 ų

Augite - refers to the group of pyroxenes. By chemical composition and crystal structure belongs to chain-type silicates. Chemical composition. Changeable; calcium oxide (CaO) 16–20%, magnesium oxide (MgO) 11.5–17.5%, iron oxide (FeO) 5–10%, iron oxide (Fe2О3) 1.5–8%, aluminum oxide (Аl2О3 ) 4.5-7.8%, titanium oxide (TiO2) 0.2-1.25%, silicon dioxide (SiO2) 46-50.5%.

Cleavage. Prismatic; the angle between the cleavage planes is 87 and 89 °. Aggregates. Solid, grainy, dense, needle-shaped. P. tr. Melts in black glass. Behavior in acids. Only titanavgite is completely soluble in boiling hydrochloric acid. It is formed by crystallization from magmatic melts, as a rock-forming mineral of many igneous rocks. Under the influence of hydrothermal solutions, it passes into hornblende (uralite) or chlorite, during weathering - into free SiO2 oxides (opals), iron hydroxides, carbonates, as well as clay halloysite and nontronite products.

Color Black with a brownish tint, greenish black, dark green

Trait Color White

The origin of the name From the Greek auge - shine

Year of discovery 1792

IMA status Valid, first described until 1959 (before IMA)

Chemical formula Ca (Mg, Fe, Al) [(Si, Al) 2O6]

Glitter glass

Transparency shines through

opaque

Cleavage perfect for {110}

Kinky conch

uneven

5.5 hardness

6

Thermal properties Melts in black glass

Strunz (8th Edition) 8 / F.01-90

Hey's CIM Ref. 16.23.1

Dana (8th Edition) 65.1.3a.3

Molecular Weight of 236.35

Cell parameters a = 9.699Å, b = 8.844Å, c = 5.272Å β = 106.97 °

The ratio a: b: c = 1.097: 1: 0.596

The number of formula units (Z) 4

Unit cell volume V 432.53 ų

Twinning is simple or multiple in {100}, and {001}

Point group 2 / m - Prismatic

Spatial group B2 / b (B1 1 2 / b) [C2 / c] {C1 2 / c 1}

Separate by {100} and {010}

Radioactivity is not radioactive

Density (estimated) 3.31 g / cm3

Density (measured) 3.19 - 3.56 g / cm3

Pleochroism visible

The dispersion of the optical axes r> v is weak to visible

Refractive indices nα = 1.680 - 1.703 nβ = 1.684 - 1.711 nγ = 1.706 - 1.729

Maximum birefringence δ = 0.026 - 0.039

Birefringence 0.032

Biaxial Type (+)

2V angle measured: 40 ° to 52 °, calculated: 48 ° to 68 °

Optical elevation high

Selection form thick-columned crystals

Classes on the systematics of the USSR Silicates

Classes by IMA Silicates

Monoclinic syngonia

Fragility Yes

Additionally In acids, with the exception of hydrofluoric acid, it does not decompose or decomposes slightly.