EARTH MATERIALS

Earth Materials

Earth Materials

Answer 1

A mineral is considered to be solid chemical substance which occurs naturally and it is built from biologeochemical processes, having some focused physical properties, chemical composition characteristics and highly ordered atomic structure. It is regarded to be naturally occurring solid with a relevant crystalline structure and definite chemical composition. Visual and material characteristic physical properties that distinguish one mineral from another are as follows:

Colour

Some minerals found to be varying colours and as well as some minerals found to be in same colours.

Streak

The colour of mineral varied differently in reflected light and powdered form. Although, colour may varies from specimen to specimen, but streak does not. Examples below convey different colours but streak is normally rusty red.

 

Lustre

Specimen appears to be more highlighted in light and distinction to be made is that of non-metallic with metallic.

Various sample with non-metallic lustre shows shinny nature but that is consider as shine of glass not metal which is shown as follows:

A sample with metallic lustre looks such as galena seems shiny and bright like polished metal.

Fracture

Minerals, which consider being fracture are disordered in a non-regular way, and lack smooth, flat, light-reflecting surfaces. One of the examples in view of two specimens that fracture irrespective to having cleavage is as follows: 

Both the white quartz and black obsidian samples shown put forward ahead conchoidal fracture defines the fracture surfaces seemed to be smooth and curved as broken glass.

Some specimen is originated with flat surfaces which are not cleavage, which considered being breakage surfaces. One of the mineral which has various crystal faces is as follows: 

Cleavage

One of the better ways to identify a cleavage face is to retain the mineral in good light. Light will replicates off cleavage faces, but in case if face is only fractured it looks to be dull. Some specimens consider being with flat cleavage surfaces, but mostly searching over flat surfaces succession the same way within or other direction of the specimen. Cleavage planes result in groups. Look at the following picture in which various planes adjacent to the plane of the page shown to shiny and flat surfaces; these consider being cleavage planes.



One of the pictures shows various stepped cleavage planes as look into the lower left-hand corner.



 

Answer 2 (a)

Rocks can be classified as per its origin. Rocks shows varying characteristics related to how they were originated. IT can be located which characteristics a rock gives, and rock can be classified based on which characteristics belong to:

Igenous Rock: It is a rock which formed as molten magma underneath the earth's surface and afterward came to the surface as an extrusion, or hold under ground as an intrusion.

Sedimentary Rocks: It is a rock originated by united sediment deposited within layers. Also known as neptunic rock, stratified rock and derivative rock.

Metamorphic Rocks: It is developed far below in the Earth's surface when known to be pre-existing rock as protolith is changed under conditions of high pressures and temperatures.

Answer 2 (b)

Difference between Igenous Rock, Sedimentary Rocks and Metamorphic ...