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to the following questions:
1. In the
coordinates you can see the rock above the garden.
Indicates what colors you can see on the rock and if
it is possible to see crystals
2. What mine does this rock come
from? What mineral is present in this rock? What
element is this rock a source of?
3. What is the most
important property of Tungten? What is the most
important use of Tungsten?
4. Add a photograph of you in the
premises, or another in which you can see an object,
or your nick on a piece of paper
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Context
In the gardens of the University of Salamanca we can see a
three-ton tungsten stone donated by the Saloro company, the
company that operates the Barruecopardo mine. A piece that joins
the collection of rocks located in front of the faculties of
Sciences and Chemical Sciences.
Barruecopardo
Mine
GEOLOGICAL CONTEXT
It is located in the Central Iberian Zone of the Iberian Massif,
in the Domain of the Shale-graywacke Complex.
MINERALIZATION
It occurs in bundles of quartz veins and veins from NS to NNE
direction, which fit into the Barruecopardo granite, located in
the metamorphic rocks of the CEG. The mineralization consists
mainly of scheelite, together with wolframite, as the main ores of
W; accompanied by arsenopyrite, which may present inclusions of
native gold and bismuth, bismuthinite and Bi-Pb-Ag sulphosalts,
and pyrite, pyrrhotite and chalcopyrite as accessory minerals.
Scheelite
Scheelite is a calcium tungstate mineral commonly found in various
geological environments. It is an important mineral of tungsten,
which is a metal known for its high melting point, density and
strength. Scheelite is named after Carl Wilhelm Scheele, a Swedish
chemist who discovered tungsten in 1781.
The mineral is typically
found in contact metamorphics, associated with granitic
intrusions. It can also occur in skarns, hydrothermal veins, and
greisen-type deposits. Scheelite is known for its distinctive
color, which can range from white to gray, brown or yellowish
brown. It often has a glassy to adamantine luster and may
fluoresce under ultraviolet light.
Scheelite has a tetragonal crystal structure, with prismatic or
tabular crystals being common. It has perfect plane cleavage and a
high specific gravity, making it relatively heavy compared to many
other minerals. Its hardness ranges between 4.5 and 5.5 on the
Mohs scale, indicating moderate hardness.
One of the notable properties of scheelite is its ability to
fluoresce under ultraviolet light. This phenomenon, known as
fluorescence, can cause the mineral to emit a bright blue or
yellow glow, depending on the impurities present. This
characteristic has made scheelite a popular mineral among
collectors.
From an industrial perspective, scheelite is an important source
of tungsten. Tungsten has various applications, including the
production of hard metals, alloys, filaments for incandescent
light bulbs, and X-ray tubes. The ore is usually processed by
flotation or gravity separation methods to obtain the desired
tungsten concentrate.
Tungsten
Tungsten or tungsten – also known as tungsten43 or, rarely used
in Spanish, wolfram – is a chemical element with atomic number 74
that is found in group 6 of the periodic table of elements. Its
symbol is W
It is a rare metal in the Earth's crust, but it is found in
certain minerals in the form of oxides or salts. It is steely gray
in color, very hard and dense, and has the highest melting point
and boiling point of all known elements. It is used in the
manufacture of fishing tackle, in the filaments of incandescent
lamps, in non-consumable welding electrodes, in electrical
resistances and, alloyed with steel, in the manufacture of special
steels.
Applications
Tungsten is a strategic
material and has been on the list of most coveted products since
World War II. For example, the United States government maintains
national reserves of six months along with other products
considered essential for its survival.
Tungsten is a metal with unique properties that make it an
essential industrial metal. Critical properties include the
highest melting point of all metals (3,410°C) and the highest
tensile strength, very high density, near diamond hardness,
thermally stable and
chemically, excellent conductor and environmentally benign.
The most important use of tungsten is as tungsten carbide in hard
metals. This is essential for industrialization as it allows high
speed drilling, cutting, pressing and/or molding of all types of
material. Other uses are in the aerospace, electronics, and
military industries.
and specialized steels/super alloys. This variety absorbs more
than 60% of the world's demand for tungsten.
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