There are rocks all over us. They are the backbones of the hills and mountains and the pillars of the plains and valleys. Under the soil on which you walk, and the deep layers of soft mud that surround the ocean basins, and bear fossils, there is a hard rock basement.
For learning about soil materials, structure and processes, rocks and minerals are important . An understanding of earth science, chemistry, physics, and mathematics is integrated into studying these natural phenomena. With an understanding of crystal geometry, the capacity to imagine 3- D structures, or knowing crystallization rates, the learner will walk away. Natural artifacts, such as rocks and minerals, add to the charm and wonder of the National Parks and, as they have been discovered, they should be left so that everyone can feel a sense of discovery. Rock, in geology, a normal and coherent accumulation of one or more minerals. Such aggregates constitute the basic unit of which the solid Earth is composed and as a rule, shape identifiable and mappable volumes. Rocks are generally classified into three key groups according to the processes that contributed to their creation.
Difference between rocks and minerals
A mineral is an inorganic element or compound that occurs naturally and has an ordered internal
structure and chemical composition, crystal shape, and physical properties that are characteristic.
Quartz, feldspar, mica, amphibole, olivine, and calcite are common minerals.
A rock, or a mass of undifferentiated mineral matter, is an accumulation of one or more minerals.
Granite, basalt, limestone, and sandstone are common rocks.
Types of rock
These groups are
(1) igneous rocks, which have solidified from molten material called magma
(2) sedimentary rocks, which consist of fragments derived from pre-existing rocks or materials
precipitated from solutions
(3) metamorphic rocks, which have been derived from igneous
or sedimentary rocks under conditions which have led to changes in mineralogical composition,
texture and internal structure.
These three classes, in turn, are divided into various categories and
types based on different criteria, the most important of which are chemical, mineralogical and
textural attributes.
The Texture
The scale, shape and arrangement of the grains (for sedimentary rocks) or crystals (for igneous
and metamorphic rocks) is the texture of a rock. The extent of homogeneity of the rock (i.e.
uniformity of composition throughout and the degree of isotropy are also of interest. The above
is the degree to which the structure and composition of the bulk are the same in the rock in all
directions.
The importance of its physical properties
In several fields of work, including geology, petrophysics, geophysics, material science, geochemistry, and geotechnical engineering, the physical properties of rocks are of interest and utility. The scientific scale varies from molecular and crystalline to earthly observations of the Earth and other celestial bodies. To reconstruct the origin of mineral deposits, geologists are involved in the radioactive age dating of rocks; seismologists formulate prospective earthquake forecasts using premonitory physical or chemical changes; crystallographers research the synthesis of minerals with unique optical or physical properties; exploration geophysicists examine the variation of subsurface physical properties.
Rocks have many uses in our lives, and their shape is impressive and attractive, so we should
preserve them as they are.
Written by /Rehab Mohammad
References
There are rocks all over us. They are the backbones of the hills and mountains and the pillars of the plains and valleys. Under the soil on which you walk, and the deep layers of soft mud that surround the ocean basins, and bear fossils,…
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