Geol 3372 Petrography Adopt a rock Research Paper

Geol 3372 Petrography Adopt a rock - Research Paper Example A field research was done where the rock was identified, and physical examination done to substantiate its characteristics. The paper seeks to explain the various types of hornblende andesite and their location around the world. An understanding on the on the plate tectonics association is important in understanding the natural processes that necessitated the formation of the rocks in the various location regions in the world. The thin report section gives the complete picture on the physical and chemical composition of the hornblende andesite detailing its mineral composition. The three minerals that make up the hornblende are Plagioclase, Sanidine mineral, and the Hornblende mineral. A hand sample showing dark gray hornblende in a very fine-grained groundmass is also illustrated further to exhibit some of the physical characteristics of hornblende. Hornblende is a common rock-forming mineral that is found in igneous and metamorphic rocks. Hornblende andesite has several different types of minerals at varied percentages (Kepezhinskas 246). The crystals vary in chemical composition, but they are all double chain in silicates with similar physical characteristics. The chemical composition of the minerals include metals, such as magnesium, chromium, calcium, sodium, iron, aluminum, silicon, fluorine, manganese, potassium, and hydroxyl (Kepezhinskas 246). The above chemical substances vary in percentages. It is composed of calcium, sodium, magnesium, iron aluminum, silicon, and Fluorine and hydroxyl groups. Different composition of these chemical substances makes the appearance or the optical properties of the rock to differ .The general optical characteristics of the hornblende andesite are: Fig 1.1 shows a hand specimen showing a dark gray hornblende in the very fine-grained groundmass (Kepezhinskas 246). The hornblende andesite minerals consist of the different chemical