Mineral Understanding
In defining minerals, until now there is still no certainty to explain the meaning of the mineral. Because there has not been any similar opinion by experts on this. But it is commonly known as two mineral defenisi, the classic defenisi that was inferred before 1977 and the compilation defenisi that was concluded after 1977.
According to classical defenisi, minerals are a naturally formed inorganic solid, homogeneous, which has a fixed crystalline shape and chemical formula. And according to the compilation defenisi, minerals are a substance found in nature with a distinctive chemical composition, homogeneous, have physical properties and are generally crystalline that have a certain geometric shape.
The thing that distinguishes the two defenisi is in classical defenisi, which includes minerals only solids or substances. And in the compilation defenisi, minerals have a wider limgkup space because it includes all the substances that exist in nature that meet the conditions in that sense. This is partly because there are several materials formed due to the decomposition or needless changes of plants and animals naturally also classified into minerals, such as coal, petroleum and soil diatome. Minerals are included in the composition of pure elements and simple salts to very complex silicates with thousands of known forms (organic compounds are usually not included).
Mineralogy is a science that learns everything about minerals. Starting from the division or classification of minerals, the introduction of mineral properties, the description of minerals and all things related to minerals.
To learn about minerals, it must first know the properties of the mineral. There are several mineral properties, namely theoretical physical properties and determinant physical properties (laboratory). Physical properties can in theory only describe some of the mineral properties and cannot be used as guidelines for determining or distinguishing existing minerals, as they are found in only a portion of minerals. The properties of minerals in theory are:
1. Cohesion Temperature
The nature of mineral cohesion is the ability or attraction between atoms of a mineral. In minerals, between similar minerals, it will have interesting appeals that cause those minerals to tend to accumulate in a certain amount in an area. This is due to the arrangement of atoms or chemical composition in fixed minerals. These attractions can also be affected by temperature. Temperatures that affect this attraction-attraction or cohesion are called cohesion temperatures.
2. Reaction to Light
Minerals tend to react to light dating or being charged to it. This reaction can generally be seen by our eyes. However, this trait cannot be used as a determinant to distinguish minerals. Due to the tendency of the onset of the same reaction in mineral-minera when exposed to light. Reactions that occur in minerals will give rise to or reveal the physical properties of minerals in determinants such as color, scratch, gloss, transparency and color rotation.
3. Crystal Stature
The stature of crystals in minerals is interpreted as the appearance of the same group of minerals that grow imperfectly because there are disturbances from the main sources of minerals as well as disturbances from the environment in which minerals occur, so minerals do not form perfectly which causes differences in mineral shape and size. Such appearances are often referred to as mineral structures.
4. Electrical Properties
The electrical properties of minerals are the ability of minerals to receive and also pass on the flow of electricity imposed on them. In minerals there are only two types of electrical properties. That is, which can conduct electricity (conductor) and which cannot conduct electricity (insulators).
5. Nature of Radioactivity
The properties of mineral radioactivity are reflected in the chemical elements contained in these minerals that can emit α, β, and γ. There are minerals that can be radioactiv such asUranium(U),Radium(Ra),Thorium(Th),Plumbum(Pb),Vanadium(V) and Potassium(K). Usually, radioactiv minerals are found in participatory minerals or minerals that are squeezed in quantities. The use of radioactiv minerals can be used as an energy source and can also be used to measure geological time by calculating half time.
6. Symptoms of Light Emission
Symptoms of light emission are symptoms of light sources produced in certain processes. For example, the process of radiation and the exit of Ultraviolet light. Phospor minerals that at night emit light are examples of continuous light emissions, as is the case with Radium(Ra) minerals. It is a wave of light emitted by minerals, where the wavelength of light is longer than a regular wave of light. There are only a few minerals that can cause light emissions such as Phospor, Radium and Flouride.
7. Smell and Taste
Odors in minerals can be observed if the physical form of the mineral can be converted into gas. The types of mineral odors are:
¨ Sulforous odor is a smell that is like the smell of Sulfur(S).
¨ Bituminous smell is a Ter-like smell
¨ Argillerous smell is a clay-like smell( soil).
As with odors, the taste of minerals can only be observed if the physical form of the mineral is converted into liquid. Here are the types of flavors in minerals:
¨ Saline flavor or salty taste.
¨ Alkaline flavors or flavors such as metal or soda.
¨ Witter flavor or bitter taste.
Any mineral that can grow without interruption will develop its distinctive crystalline shape, which is an outward face produced by crystalline structures. There are minerals in an Amorphousstate, which means they have no buildings and their own crystal line (e.g. glass & opal). Each crystallize will be better if the process is calmer and slower.
Mineral Formation Process
The process of forming minerals both of economic value, and that are not of economic value, is very important to know and learn about the process of formation, obtainability and utilization of these minerals. Minerals that are economical can be known how they exist and their availability by paying attention to the association of minerals that are not usually economically valuable. From several exploration processes, investigations, searches for mineral deposits, it can be known that the existence of a mineral is inseparable from several factors that are very influential, including the number and distribution of chemical elements, biological and physical aspects.
In general, the process of mineral formation, both metal and non-metallic types can be formed due to the mineralization process caused by magma activity, and economical minerals in addition to magma activity, can also be produced from alteration process, namely minerals that are altered from minerals that have existed due to a factor. In the process of mineral formation both mineralized and alteration regardless of certain factors that will then be discussed in more detail for each type of mineral formation.
According to M. Bateman,the mineral formation process can be divided into several processes that produce certain types of minerals, both economically valuable and minerals that are only as gangue minerals.
1. Magmatis Process
This process is largely derived from ultra-alkaline primary magma, and then cooling and freezing forms silicate minerals and ore. At high temperatures (>600°C) the stage of magmatic liquido begins to form minerals, both metal and non-metallic. Mineral associations formed according to the cooling temperature at the time. This magmatic process can be divided into two types, namely:
1. Early magmatis, which is divided into:
¨ Disseminated,e.g. Diamond
¨ Segregation, forexample Crhomite
¨ Injection, For example Kiruna
2. Late magmatis, which is divided into:
¨ Residual liquid segregation,for example Magmatis Taberg
¨ Residual liquid injection, e.g. Adirondack magmatis
¨ Immiscible liquid segregation, e.g. Sulfide Insizwa
¨ Immiscible liquid injection,e.g. Vlackfontein
2. The Process of Pegmatism
After the process of magmatic formation, the remaining solution of magma (solution of pegmatism) consists of liquids and gases. This sediment stage ranges from 600°C to 450°C in the form of a residual magma solution. Rock associations are generally Granite.
3. Pneumatolisis Process
Once the temperature starts to drop, between 550-450°C, the accumulation of gas begins to form a pneumatolisis trap and the remaining solution of magma becomes more diluted. Volatile elements will move through the existing frozen rocks and surrounding side rocks, then will form minerals both due to the sublimation process and because of the reaction of the volatile elements with the rocks that are breached so that mineral deposits are formed calledpneumatolitis minerals.
4. Hydrothermal Process
It is a mineral forming process that occurs by the influence of very low temperature and pressure, and the magma solution that was formed earlier. Broadly, hydrothermal mineral deposits can be divided into:
1. Hypothermal deposits,the characteristics are:
¨ Freezing pressure and temperature are relatively high.
¨ Deposits in the form of veins and coroks are associated with intrusion with great depth.
¨ Mineral associations in the form of sulphides, e.g. Pyrite, Calcopyrite, Galena and Spalerite as well as iron oxides.
¨ Granite intrusions are often au, pb, sn, w and z metal deposits.
2. Mesothermal deposits,which are characteristic:
¨ The pressure and temperature are lower than hypothermal deposits.
¨ The deposits are associated with acid-base frozen rocks and are close to the earth's surface.
¨ Texture due to "cavity filling" clearly visible, although often undergoing the replacement process among others in the form of "crustification" and "banding".
¨ The mineral association is sulfide, e.g. Au, Cu, Ag, Sb and Oxide Sn.
¨ Enrichment processes are common.
3. Epithermal deposits,the following characteristics:
¨ The lowest effect pressure and temperature.
¨ Replacement textures are not broad (rare).
¨ Deposits can be near or on the earth's surface.
¨ Most textures are layered or inthe form of (fissure-vein).
¨ The typical structure that often occurs is the"cockade structure".
¨ The association of metal minerals in the form of Au and Ag with minerals "gangue" in the form of Kalsite and Zeolite in addition to Quartz.
The forms of mineral deposits can be found as hydrothermal sediment process is as cavity filling. Cavity filling is a mineralization process in the form of filling opening spaces (cavities) in rocks consisting of minerals deposited from solutions on rock openings, which are Fissure-vein, Shear-zone deposits, Stockworks, Ladder-vein, Saddle-reefs, Tension crack filling, Brecia filling (volcanic, tectonic and collapse),Solution cavity filling (caves and Channels), Gash-vein, Pore-space filling, Vessiculer fillings.
5. Metasomatic replacement process
It is prsoses in the formation of epigenetic mineral deposits dominated by the formation of hypothermal, mesothermal and very important deposits in the epithermal group. Ore minerals in contact metasomatic deposits have been formed by this process, where this process is controlled by the enrichment of sulfide elements and dominance in the formation of other mineral sediment elements. Replacement is defined as the process of a very important solution in the form of capillary dissolving and deposition that occurs simultaneously where there is the replacement of one mineral or more into other new minerals. Or it can also be interpreted that mineral replacement requires ions that do not have ions in general with chemicals replaced. Replacement of minerals carried in solutions and chemicals brought out by the solution and is an open contact divided into: Massive, Lode fissure, and Disseminated.
6. Sediment process
Divided into iron deposits, manganese, phosphate, nickel and so on.
7. Evaporation Process
Consists of evaporation of the sea, lake and groundwater.
8. Residual and Mechanical Concentration
Consists of:
¨ Residual concentration in the form of manganese residue deposits, iron, bauxite and others.
¨ Mechanical concentration (placer deposits), inthe form of rivers, beaches, alluvials and eolians.
9. Supergen enrichment
10. Metamorphism
It is divided into deposits of thermomorphic deposits and deposits of metamorphism.
Rock Forming Minerals
Rock-forming minerals can be distinguished above:
- Felsicminerals, composed of minerals that are bright and bright and have a small or light weight.
Examples: Quartz, Feldspar and Feldspatoid
- Maficminerals, composed of minerals that are dark in color and have a large or heavy type of weight.
Examples: Olivin, Amphibole and Pyroxin.
Felsic Minerals
A. Quartz (Quartz)
Quartz minerals have a hexagonal crystalline system (prism, bipyramid and its combination. The chemical formula tau the chemical composition of quartz is SiO2. the weight of this type of mineral is 2.65 with a hardness level (H) worth 7. The color in quartz can be clear or murky when found together with feldspar, there is often inclusion of gas, liquid or mineral oiling in it, which is the element of the pollutant and strongly affects the color of the quartz, so that from the color indicated can be estimated the purity of the quartz. There are no hemispheres in the quartz. And quartz is also widely used in the industry, especially related to glass.
Quartz or sometimes called"silica". It is the only rock-forming mineral consisting of silicon and oxygen joints. It generally appears with colors such as smoke or"smooky",also called"smooky quartz". Sometimes also with a purple or red-lembayung (violet) color. Such quartz names are called"amethyst",red massip or pink, yellow to brown. This variety of colors is due to the absence of other elements that are not clean.
B. Feldspar
Feldspar can be classified into two large groups, namely:
1. Alkali feldspar consisting of orthoclase, microklin, sanidine, anorthoclas,
pertite, and antipertite.
2. Plagioklas feldspar consisting of albite, oligoclas, andesine, labradorite,
bytownite and anorthite (calsic).
In practice performed in a megascopic way (without aids), this feldspar can only be distinguished into Alkali feldspar (Orthoclasal domination) and Plagioclas.
¨ Orthoclase (Potassium feldspar)
Orthoclase is a member of the mineral feldspar. Orthoklas (Potassium feldspars)is a silicate mineral that contains elements of Potassium and its crystalline shape is prismatic, generally red to white.
This chemical formula or chemical composition of Orthoclas is KaISi3O8. The weight of this type of mineral is 2.6 with hardness 6. The crystal system is monoklin, has a glass gloss, and a twisting stature. Orthoclase is used as a raw material in the ceramics industry.
¨ Plagioklas feldspar
Plagioclase minerals are members of the feldspar mineral group. It contains elements of Calsium or Sodium. Feldspar crystals are prismatic in shape, generally white to gray, shiny glasses. Sodium-containing plagioclas is known as the mineral Albite, while ca-containing is called An-orthite.
The crystal system of this plagioclas is a triklin with a type weight of 2,26-2.76. This plagioclas has a hardness value of 6 and has a twin-shaped hemisphere. The chemical composition of this mineral is NaCaAl2Si3O8.
C. Feldspatoid
This feldspatoiid mineral is also referred to as a substitute for feldspar, because it is formed when in a rock there is not enough SiO2. If there is a free SiO2 (quartz) rock, then what will form is feldspar and will not form feldspatoids. Minerals including feldspatoids are nepheline, leusite, sodalite, scapolite, carcrinite and analcite. But all you can find is nepheline and leucite.
¨ Nepheline (KNaAl2Si2O4)
Nepheline is a mineral included in the hexagonal crystal system, although its shape is rare, generally massif and fine grain. The color of this mineral is yellowish white to reddish gray. The hardness value of nepheline is 5.5 to 6 with a type weight (SG) of 2.55 to 2.65. The gloss on the nepheline is a glass gloss, but some have a glossy oil. The hemisphere of the surface is prism-shaped in large crystals. Nepheline is often found in the formof "dike"on frozen rocks.
¨ Leucite (KaISi2O8)
Leucite minerals are included in the isometric system in the general form of trapezohedron. This leucite has a small and smooth shape, and is known by the name fine grain matrix. The hardness value in this leucite mineral is 5.5 to 6 and the type weight value is 2.45 to 2.5. leucite color is generally grayish white.
Mafic Minerals
A. Olivine ((Mg,Fe)2SiO4)
Olivine is a group of silicate minerals composed of iron (Fe) and magnesium (Mg) elements. Green olivine minerals, with glass gloss, form at high temperatures. This mineral is commonly found in basalt and ultramafic rocks. Rocks whose entire mineral consists of olivine minerals are known as Dunite rocks. Olivine is sometimes also called crysoline.
Olivine has a glass gloss appearance and a hardness value(H) of 5.5-7.0. This mineral has a type weight (SG) of 3.27-4.27. In general olivine is found in alkaline frozen rocks such as gabbro, basalt, peridotite and dunite.
B. Pyroxin
Pyroxins are a complex group of silicate minerals and have close relationships in crystal structure, physical properties and chemical composition although they crystallize in two different systems, namely orthorhombic and monoklin. Structurally, pyroxin consists of an endless and tetrahedral chain of SiO4 bound together laterally by Mg and Ca metal ions that are bound to oxygen, and do not bond directly with silicon.
The general chemical composition of pyroxins is W1-p(X,Y)1+pZ2O6. Where symbols W, X, Y and Z indicate elements with the same atomic radius.
W = Na, Ca Y = Al, Fe, Ti
X = Mg, Fe, Li, Ma Z = Sid an Al in small quantities
The shape of pyroxin crystals is prismatic with specific hemispheres. In volcanic frozen rocks, pyroxin is low Calcio Augote or Pigionite, while in plutonic rocks, pyroxin is Augite.
C. Amphibole (Horblende)
Amphibole is a group of silicate minerals in the form of prismatic or crystals that resemble needles. Amphibole minerals generally contain iron (Fe), Magnesium (Mg), Calcium (Ca), and Aluminum (Al), Silica (Si), and Oxygen (O). Hornblende appears dark green. This mineral is found in many types of frozen rocks and metamorphic rocks.
D. Mica
Mica is a group of mineral silicate minerals with varying compositions, from potassium (K), magnesium (Mg), iron (Fe), aluminum (Al) , silicon (Si) and water (H2O). The structure of mica is a type of tetrahedron in sheets. Each SiO4 has three oxygens and one oxygen free., so its composition and valence are represented by (Si4O10)a.4.
The general formula of mica can be written: W(XY)2-3Z4O10)OHF)2 where W = K (Na in Paragonite mineral is very good on sekiot).
X,Y = Al, Li, Mg, Fe
Z = Ai, Al.
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