Quartz Quartz is hexagonal and commonly occurs as crystals ranging in size form microscopic to crystals weighing several tons. Where it crystallizes unhindered by other crystals, such as in cavities in rock or in a liquid containing few other crystals, it shows well-developed hexagonal prisms and sometimes showing apparent hexagonal pyramids or dipyramid. When it crystallizes in an environment where growth is inhibited by the surroundings, it rarely show crystal faces. It is also found as microcrystalline masses, such as in the rock chert, and as fibrous masses, such as in chalcedony. Vitreous lusture. As visible crystals, Quartz is one of the more common rock forming minerals. It occurs in siliceous igneous rocks such as volcanic rhyolite and plutonic granitic rocks. It is common in metamorphic rocks at all grades of metamorphism, and is the chief constituent of sand. Because it is highly resistant to chemical weathering, it is found in a wide variety of sedimentary r
FORMATION OF PETROLEUM BY THEORIES FIGURE : 1.1 PETROLEUM : Petroleum is also said to be an rock oil , which is a most important mineral fuel which is a complex mixture of hydrocarbon which comprises some minor impurities of nitrogen , oxygen , sulfur . In other word liquid petrol is said as crude oil , petroleum gas is also known as natural gas Semisolid to solid form of petroleum is asphalt , tar, pitch, bitumen , etc... The formation of petroleum comprises two theories they are : INORGANIC THEORY ORGANIC THEORY INORGANIC THEORY : Inorganic theory includes:- Brethelot’s alkaline carbide theory Mendelcef’s carbide theory Moissan’s carbide theory Cosmic theory Brethelot’s alkaline carbide theory : This theory explains that the carbon-di-oxide reacts with alkaline metal in the interior of the earth at high temp