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
ORIGIN OF THE PLANET BY BIG BANG THEORY figure (1.1) When a dust particle exploded ,a kind of shock waves are created . the shock waves flattened the clouds like a accretionary disk Accretionary disk forms as gravity pull of matters together,which consist of large stars times went out of matters continues to form this kind of disk This kind of clouds and nebula consist of volatile and refractive chemical compound while the refractive materials are IRON , ALUMINIUM , MAGNESIUM , POTASSIUM , CALCIUM , AND SILICONS . where the volatile materials are HYDROGEN , HELIUM , METHANE , AMMONIA , WATER , AND CARBON-DI-OXIDE . It is the modern theory about origin of solarsystem . It remember how nebular have formed It also which similarly related to the nebular hypothesis about the origin of nebula , comets ,asteroids and meteoroids Big bang theory explains the expansion of universe It was first explained by Edwin hubbl