Minerals

Anonymous

 Minerals

Minerals are naturally occurring materials. a material need to be five requirements to be considered as a mineral

  1. must be naturally occurring
  2. must be inorganic
  3. must be a solid
  4. having a definite chemical composition
  5. the atoms that make the substance must be arranged in an orderly structure
  • There are almost 4000 minerals on earth
  • minerals are building blocks of Rocks 
Identifying Minerals

i)Color 
color is not the most reliable way to identify minerals, the same mineral may exist in different colors, but in opaque and metallic minerals color is a reliable indicator to identify minerals

ii)Hardness
hardness is measured on the Mohs scale, it is like a scratch test. here we are supposed to take an unknown mineral and scratch with an item of known hardness (or vice versa). Since some minerals may leave a powdered streak on the item being scratched (or the known hardness item may leave a streak on the sample) one must rub the "scratch" with a finger to see if it is really a scratch or just a powder streak that rubs off.  If a mineral produces a powder streak on the item being scratched then it is probably softer than that item.  (Conversely, if the item leaves a streak on the sample it is softer than the sample.)

iii)Luster
Luster refers to the reflection of light off the mineral's surface. luster can be classified based on whether the mineral is metallic or non-metallic. 

iv) Cleavage and Fracture




when a mineral breaks randomly it will have a jagged irregular shape. such irregular breakages are referred to as Fractures. they are of two types i) conchoidal and ii) uneven. 

not all minerals break randomly some of them breaks in a certain way that it looks like they have been cutted in such a way such breakages are referred to as Cleavage

v) Streak

it refers to the color of a mineral as a powder. to make the powdered sample of a mineral we need streak plates, streak plates are ceramic tiles, we rub our mineral sample against it to create powder and observe the color of that powder. most minerals leave a color streak but a few of them leave a distinctive color that can be used to identify them.