This mineral contains three species and varieties.
Elbaite: includes varieties such as ancoita (colorless), rubellite (pink red), Verdelite (green) and indigolita (in blue colr. Dravite, brown. Plover, red tourmaline Ferrous .
The tourmalines are in the form of prismatic crystals, columnar or acicular, often are grouped to form radial or fibrous aggregates.
are unaffected by the acids. magnésiferas varieties blend easily, while ferriferous and litinégeras are infusible.
The tourmalines are common minerals of magmatic origin in pegmatites and granites. Some varieties, such as dravite, are common in metamorphic limestone. Sometimes appears in detrital sediments.
Along with the quartz and cassiterite, tourmaline is the third mineral interest in mining assets Logorán and Cerro San Cristobal.
This issue can be seen at the Museum of Achievement.
Tourmaline Pyrite in Quartz Ibores Villuercas Jara
is a mineral composed silicon dioxide (SiO2). It is not likely to peel, because crystallizes in the trigonal (rhombohedral). Colorless in pure can take many shades if you bring impurities (APO). Its hardness is such that it can scratch the common steels.
is the most abundant mineral in the earth's crust and the major component of many igneous rocks (like granite), metamorphic (quartzite and gneiss) and sedimentary (sand and sandstone). The most common crystals are prismatic and bipyramidal trapezohedral. The twins are most abundant in Brazil and Dauphine. Often in the form of pockets of great beauty. It also appears in blobs, usually milky.
Most quartz is magmatic origin, although can also be formed from hydrothermal solutions and metamorphic processes.
Some microorganisms, such as certain algae and foraminifera, have a shell of SiO2. Quartz deposits are widespread in the crust.
well crystallized quartz and transparent used in the manufacture of optical instruments and precision electronics. Some varieties are seen as precious and semiprecious stones. is used as a flux in metallurgy, in the industries of glass and ceramics, as an abrasive, etc..
We can find different varieties with different optical characteristics. Fenocristalinas varieties are presented in well-developed crystals, from transparent to translucent. These varieties can be found:
Amethyst.
rock or quartz crystal hyaline, colorless, transparent and clear, widely used in jewelry and in the manufacture of optical instruments.
Smoky Quartz: is brown. Morion is a variety of smoky quartz stone highly prized as fine. Citrine Quartz
: light yellow to golden yellow.
Jacinto de Compostela: a reddish color.
Rose Quartz.
Quartz quartz or sapphire blue.
Ojo de tigre: yellow or brown.
Hawk Eye: blue.
Cat's eye: gray-green.
Chalcedon or cryptocrystalline varieties: made up of microscopic crystals, usually of bright waxy and translucent to opaque. Within this group we can find Agatha.
Onyx or Onyx: zoned structure with light and dark layers. Plasma
: green due to inclusions of chlorite and amphibole.
prase: dark green. Flint
: greyish, widely used since the time for making cutting tools because of its remarkable hardness and its causes fracture edges sharp.
or sardonic sardonyx: orange.
Heliotrope: dark green with red spots. Carnelian or canicola
: bright red uniform. Jasper
: intense and varied coloration due to the presence of inclusions.
Opal: with the same composition as quartz but no crystalline structure. It is an amorphous mineral.
Quartz is a major mineral that appears in our region and that all mining points are remnants of quartz crystals. Logrosán can be found in the finest examples of quartz crystals that can be found in Extremadura.
Etymology: German Quarz. Crystallization: trigonal system (rhombohedral). Density: 2.65. Hardness: 7. Color: colorless or with different colors. Brightness: vitreous to greasy. Raya : white.
Mining is an activity in the short term but long-term effects.
is true that humanity needs certain minerals to meet some of their needs, whether basic or not. It is also true that excessive consumption of part of humanity is destroying the livelihoods and the environment from another part of humanity living in areas impacted by mining and can be your means of survival.
Because of its impacts, mining is one of those activities should be strictly controlled at all stages, from exploration and exploitation to transportation, processing and consumption.
impacts of mining are related to the mine itself, with the disposal of mine waste, transportation of ore and processing it, which often involves or produces hazardous materials . We can meet with different constructions and mining for example we can see underground and opencast mines . Generally, underground mining has less environmental impact of opencast mines . The disturbance in the earth's surface is lower, but may also have effects on water contaminating it with acids and metals and intercepting aquifers. Although this is the fact that workers working in this type of mining are exposed to more dangerous situations than those working in open pit mines, the risk of subsidence, poor air quality and underground explosions.
Currently, over 60% of materials are extracted by the mode of surface mining, which causes the devastation of the ecosystem in which it is installed (deforestation, pollution and disturbance water, habitat destruction). Within this type of mining are distinguished, among others, open pit mines (usually metal hard rock), the quarries (for construction and industrial materials such as sand, granite, slate, marble, gravel, clay , etc.), and leach mining (application of chemicals to filter and separate the metal from other minerals).
The appearance of the open pit (or open pit) is the large terraces arranged in deep wide pits in the middle of a desolate landscape, bare and devoid of living resources. The operation usually begins with the removal vegetation and soil, then dynamite widely and removed the rock and the materials located above the ore up to the reservoir, where it again dynamited for smaller pieces. New technologies that allow better performance in the speed of mineral extraction and processing, increase environmental problems as waste materials not normally revert to the restoration of the site.
Quarries are surface mines, very similar to open-pit mines, because the end result of their exploitation is also a barren landscape with deep trenches between wide steps. The assault on the environment itself it generates this type of mining is exacerbated by its proximity to urban areas, as it seeks to reduce transport costs for greater profitability. This proximity generates new environmental problems, since the excavations, which have no cover, end up as urban landfills, in addition to affecting surface water and groundwater near the farm.
leaching in mining chemicals are used (eg sulfuric acid in the case of copper or a solution of sodium cyanide for gold) to dissolve (leach) the metals in the mineral matter that contains them, obtaining a very high recovery rate. Can result in the variation of in situ leaching (drilled with holes intact rock and add the solvent) or very frequent leaching heaps of crushed ore. The chemical solutions used not only release the desired metals but also mobilize heavy metals (like cadmium), so that surface water and groundwater are often contaminated.
Although the environmental impacts of mining vary depending on type of ore and mining, it is an inherently unsustainable because it involves the exploitation of a nonrenewable resource by destructive or contaminating processes such as crushing, grinding, washing and classification of minerals, refining and smelting. Today is doubly destructive for its large scale and the technology that has increased its production capacity.
environmental impacts produced by the mines are divided into air, landscape, water, soil, fauna and flora (Macias, 1996).
