Mineral & Petrology In Geotechnics & Applied Geology Enrollment no. Name Guided By Chaudhary Dinesh K. Prof. V.R.Sharma Chaudhary Sanjay P Chauhan Ankit A Chauhan Pragnesh R Gameti deep B. Applied Mechanics Department Government Engineering College Palanpur

Definition of Mineral  A mineral may be defined as natural, inorganic, Homogeneous, solid, substance having definite Chemical composition and regular atomic structure.

The Physical Properties of Minerals Color Streak Luster Specific Gravity Special Properties Other Properties Chemical Tests Hardness External Crystal Form Cleavage

Colour Most minerals are coloured by a limited number of metals present as impurities. The most common elements affecting colour are: chromium, iron, manganese, titanium and copper. It is chromium which produces the intense red of ruby and the brilliant green of emerald. Minerals tend to occur in a range of colours, and colour patterns which help to identify them

luster Refers to the way light reflects from the surface of the mineral. There are two types of luster, Metallic: looks like polished metal. Nonmetallic: does not look like polished metal. Nonmetallic can be shiny or dull.

Hardness Hardness is defined as the resistence of a mineral to scretching.It is on the most important diagnostic properties of mineral. Is measured by how easy it is to scratch.  Geologists order the hardness by… 1. Scratched by a fingernail. 2. Scratched by a penny. 3. Scratched by a nail. 4. Scratched by a diamond.

Ex. 1: Diamonds are the hardest mineral, so it scratches every mineral.

Specific Gravity It was Archimedes who first worked out the principal of specific gravity or relative density. Specific gravity is defined as the ratio of the weight of a substance compared to that of an equal volume of water. For example, a piece of galena (lead ore), with a specific gravity of 7.4 will feel much heavier than a piece of quartz of a similar size but with specific gravity of 2.65, reflecting the way the atoms are packed together.

Streak The colour of the mineral powder is called streak. Sometimes the colour of the streak can be used to identify the mineral. Eg. Haemetite a black mineral has a red streak. No other black mineral has a red streak.

Cleavage It is defined as the tendency of the crystallized mineral of break along certain defined direction, less smooth, plane surface the planes along which the mineral breaks are called the cleavage planes. These planes are related to the lattice work of the mineral's atomic structure. Distinct cleavage planes can be illustrated in this box mica specimen

Petrology Petro means Rocks. Logos means study. Petrology deals with study of rocks.  Rocks:  The rocks may be defined as aggregates of minerals. Some rocks, such as quartz and marble, contain grains of one mineral only but most are commposed of a veriety of different minerals.

Petrology is subdivided into three branches. Igneous petrology Sedimentary petrology Metamorphic petrology

Igneous Rocks Sedimentary RocksMetamorphic Rocks dfdfdExternal processes (W+T+D+L) dfdfdExternal processes (W+T+D+L) dfdfdInternal processes (H+P+F) dfdfdInternal processes (H+P+F) Melting under internal Processes Solidification

Where, External Processes : W = Weathering T = Transportation D = Deposition L = Lithification Internal Processes : H = Heat P = Pressure F= Fluids such as water

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