Petrology

Petrology which focuses on the field of geology that studies rocks, and the conditions of its formation. there are three branches of petrology, associated with the three types of rocks : frozen, metamorphic, and sedimentary. petrology word itself comes from the greek word petra, which means stone.

• Igneous petrology focuses on the composition and structure of igneous rocks ( rocks like granite or basalt rock that has crystallized from melt to lava ). igneous rocks include volcanic and plutonic rocks.

• Petrology of sedimentary rocks focus on the composition and structure of sedimentary rocks ( rocks like sandstone or limestone that contains sediment particles bound to the matrix or finer material ).

• Metamorphic petrology focuses on the composition and structure of metamorphic rocks ( rocks like slate or marble stone that originated from sedimentary rocks or frozen, but already past the turn of the chemistry, mineralogy or structure due to the extreme conditions of pressure, temperature, or both )

Petrology mineralogy using classical field, petrographic microscopic and chemical analysis to describe the composition and structure of rocks. experts also incorporate modern petrological and geochemical principles in geophysical research trends and geochemical cycles and the use of experimental thermodynamic data as well as to better know the origin of rocks.
experimental petrology using high pressure equipment, high temperature to investigate the geochemical and phase relationships of natural and synthetic materials at elevated pressures and temperatures. the experiment is particularly useful weeks to investigate the rocks on top of the crust and upper mantle side that rarely survive the journey to the surface in the original condition.

Mineral chemistry
Chemical composition of the mineral is a fundamental subject, because most character-trait minerals / crystals depend on them. character-trait mineral / crystal is not just dependent on the composition but also on meruang arrangement of constituent atoms and the bonds between the atoms making up the crystal / mineral.
Power that binds atoms ( or ions, or ion group ) of crystalline substances in the form of electrical in nature. very kind and intensity associated with the character as well as the chemical-physical properties of minerals. hardness, cleavage, melting power, electrical and thermal conductivity, and thermal expansion coefficient associated with the immediate holding capacity.
mineral chemistry is a science which is shown at the beginning of the 19th century, after he presented the law of composition remains by proust in 1799, dalton atomic theory in 1805, as well as the development of methods of accurate quantitative chemical study. because the mineral chemistry based on knowledge about the composition of the mineral, chemical possibilities and limitations of the study should be identification of minerals properly.

Chemical principles related to mineral chemistry : 

The law of constant composition by proust ( 1799 ) :
mass ratio of the elements in each compound is fixed

Dalton atomic theory ( 1805 ) :
each element is composed of extremely small particles and form balls like atom in question.
atoms of the same element the same shape but of the same elements that are not shaped the same. atoms can be chemically bonded to the molecule.

Physical characters of minerals
determination of mineral names can be done to compare the character-physical properties of the minerals in minerals with other minerals. character-physical properties of minerals include : color, luster ( luster ), hardness ( hardness ), scratch ( streak ), cleavage ( cleavage ), fractional ( fracture ), structure / form crystals, heavy , the characters in ( tenacity ), and magnetism.

Crystal form
of the existence of something that all crystals can be determined by geometry, shrinkage etahui-field corner. till now there are only 7 types of crystal systems. basic classification system regarding the crystal there are three, namely :
1. number of crystal axis,
2. the location of the crystal axes with one another
3. parameters used for each axis of the crystal