There are several different categories of texture that rocks can be divided: Texture refers to the size and arrangement of the minerals or grains that make up a rock. (III) In your own words, write the definition of rock texture. We'll deal with each of these elements of texture separately and see what they can tell us about how the rock originated. If clastic, use the clastic rock chart. Click each image to see a larger version plus information about the rock's texture. The texture of igneous rocks can be analyzed to understand how the rock became solid or crystallized from liquid, melted rock. From this point, the following description of sedimentary rocks should guide you to the appropriate rock name. The texture of a rock provides a clue whether the magma cooled fast or slowly and where the rock was formed. The resulting rock will have a granulitic texture that is similar to a phaneritic texture in igneous rocks. Each type of rock has a distinctive set of minerals. In geology, the texture of a rock refers to the size, shape, and arrangement of grains or crystals in the rock. The various textures observed are: • Phaneritic Texture-Large crystals can be observed over the rock surface by naked eyes. A rock may be made of grains of all one mineral type, such as quartzite. To answer the questions, use the 'Information Sources' link buttons. Some granites are foliated. Add details to your answers for question 1. There are six main types of textures; phaneritic, aphanitic, porphyritic, glassy, pyroclastic and pegmatitic. Much more commonly, rocks are made of a mixture of different minerals. Igneous rocks are further divided on the bases of its dissimilarities in textures and hence extrusive and intrusive rocks are obtained. It has colorless grains, and it is mottled in white, red, pink, grey or dark grains. The tiniest bits of rock make up sand and soil . Rock, or stone, is a hard material made up of one or more minerals . The lower parts of this layer are solid rock, or bedrock. Igneous textures include the rock textures occurring in igneous rocks.Igneous textures are used by geologists in determining the mode of origin igneous rocks and are used in rock classification. If the texture is (micro) crystalline, you are dealing with a chemical rock. Composition refers to both the types of minerals within a rock and the overall chemical makeup of the rock (the two are obviously related). Texture of a rock is the appearance of the rock and how one feels touching it. The size and shape of the mineral grains or crystals and the pattern of their arrangement give a texture to the rock. If the texture is (micro) clastic, you must determine whether the rock is clastic or bioclastic. TEXTURE Texture refers to the sizes and shapes of grains, the relationships between neighboring grains, and the orientation of grains within a rock. Rock makes up the outer layer of Earth, called the crust. It is classified as acid plutonic igneous rock, and it commonly occurs in batholiths. Igneous rocks are classified according to their texture and composition. {Hint: purple arrows in figure 2.2, page 27 are “processes” that lead to the formation of different rock groups} In general, the grain size of metamorphic rocks tends to increase with increasing grade of metamorphism, as seen in the progression form fine grained shales to coarser (but still fine) grained slates, to coarser grained schists and gneisses. Texture of Igneous Rocks: Factors Explaining Texture of Igneous Rocks: The following three factors will primarily define the type of texture in a given igneous rock: (a) Degree of Crystallization: ADVERTISEMENTS: In an igneous rock, all the constituent minerals may […] {Hint: Read page 28} Page 3 of 7 (IV) Name the process by which sediment is transformed into sedimentary rocks. Granite also tends to have coarse intergrowths of feldspars and quartz that form a graphic texture. ADVERTISEMENTS: In this article we will discuss about the texture and classification of igneous rocks. Broken bits of rock lie on top. Rocks are identified primarily by the minerals they contain and by their texture. !