Cue On OCT: Study Guide

Assignment #1 - DUE ON OCT. 14

1. Define the following and distinguish from each other:
• Mineral - a substance that has a definite chemical composition that usually solid and inorganic, and it is a naturally occurring homogenous substance that has a varying crystal structure.
• Crystal – a solid substance whose elements, like atoms, molecules, and ions are arranged in a pattern or highly ordered structure when viewed in a microscope.
• Rock – any solid material having a unique inorganic and/or organic composition. It forms the part of the surface of the earth and some planets. It has three types, igneous, sedimentary, and sedimentary rock.
• Mineralloid – a mineral-like substance that is not in crystal form. Like the minerals, it

• Crystal is a formation that is one prerequisite of a Mineral. Mineralloid doesn’t have a crystal system so it lacks one prerequisite to be a mineral. Minerals are one of the substances that forms the Rock. Some rocks are made up of decayed organisms that went through time and mixed up with other elements while fossils are dead organisms that are preserved due to some natural reasons.

2. Different Crystal systems briefly describe and illustrate each
• Cubic System – It is also known as the isometric system. All the three axes are in equal length and intersects at a right angle

• Tetragonal System – Two axes are equal of length and are in the same plane, main axis is either shorter or longer, and like the cubic system, all the three axes intersect at right angles

• Hexagonal System – Three out of four axes are in one plane, of the same length, and intersects and intersects each other at angles of 60 degrees. The fourth axis is of a different angle and intersects others at a right angle.

• Trigonal System - It is also known as the Rhombohedral System. Axes and angles in this system are similar to the hexagonal