EARTH MATERIALS

Earth Materials

Answer 1.

Minerals are the natural substances and are the building blocks of rocks. Some of the geologists define minerals as, a chemical composition with fixed structure which are naturally occurred, concrete, and crystaline and are non-living substances (FARINA, 1986).

Colour

Minerals are mostly differentiated through their colours. Many of the minerals are having same colours and it is sometimes difficult to differentiate between the same minerals of same colours. For example, olivine, epidote, and actinolite are some of the minerals which are similar in colour. On the other hand, there are some minerals which can be found in different colours for example, quartz. The reason for same colours of different minerals or same minerals with different colours is due to their structure and crystal composition which give colour to any mineral.

Streak

Streak is the colour of the mineral when it is cursed in a powder form. According to the streak property of the minerals, the colour of the minerals usually changes when they are transformed from raw form into powder form. Almost, every mineral contains this property. For example, Calcite is a mineral which is found in many colours, different shapes and varieties. But, whenever you convert any sort of calcite into powder form, it will always in the white streak. Similarly, streak of the gold is always being in yellow.

Lustre

Lustre is the type of mineral characteristic which is found in every mineral. It describes the light that every mineral reflects. It also determines how dull or active the mineral is. There are different specimens in every mineral, it is the quality of the geologist who have expertise in their eyes how they examine each specimen. It used in the identification of the minerals that have same lustre for example grease and wax.

Morphology

Morphology is the shape or occurrence that mineral commonly has. A mineral is highly reflected through an environment in which it is formed. Minerals can be form in three solid dimensional shapes when they are free to shape in any form without any restriction. Crystal lattice is the structure in which the shape of a crystal is identified through the display of atoms in their structures. Fracture and cleavage

Fracture is the characteristic of the minerals when a mineral is break into chip form. Whereas, Cleavage is the characteristic of the mineral when it is break into smooth plain form. There are three factors through which cleavage are often measured, the cleavage's quality, the number of sides which exhibit cleavage and the habit of the cleavage.

Answer 2(a).

Rocks are nature gifted and are considered as a sort of minerals. Rocks are classified into three categories. Following are the categories of rocks.

Igneous Rocks

Igneous rocks are such rocks which are formed through crystallization by molten or called magma. Igneous rocks further have two types one is volcanic rock which is also known as extrusive rocks and the other one is plutonic rocks which is also known as intrusive. The example of igneous rocks is andesite and ...