Mineralogy Manual
Minerals are the materials of which the earth's crust consists and are therefore among the most common objects of daily observation. A mineral may be defined as a naturally occurring substance having a definite and uniform chemical composition with corresponding characteristic physical properties. This eliminates all artificial products of the laboratory which may conform to the last part of the definition. It also eliminates all natural products of organic agencies, since they will not show the uniform chemical and physical characters demanded of a mineral.
Minerals are the materials of which the earth's crust consists and are therefore among the most common objects of daily observation. A mineral may be defined as a naturally occurring substance having a definite and uniform chemical composition with corresponding characteristic physical properties. This eliminates all artificial products of the laboratory which may conform to the last part of the definition. It also eliminates all natural products of organic agencies, since they will not show the uniform chemical and physical characters demanded of a mineral.
In the form of rocks, minerals make up the solid matter of the earth's crust. But in the great majority of cases a rock is not made up of a single mineral, but is a more or less heterogeneous aggregate of several different species. A few rocks, like limestone and quartzite, consist of but one mineral in a more 01' less pure state. In addition to occurring as essential and integral parts of rocks, minerals are found distributed through them in a scattered way, 01' in veins and cavities. Water is a mineral, but generally in an impure state from the presence of other minerals in solution. The atmosphere and all gaseous materials set free in volcanic and other regions are mineral in nature.
Characters of Minerals
Minerals, as previously stated, have a definite chemical composition. This composition, as determined by chemical analysis, serves largely to define and distinguish the species. Owing to difference in composition, mineral s exhibit great differences when subjected to the action of various chemical reagents, and these peculiarities are a means of determining the kind of mineral under examination in any case. The department of the science treating of the composition of minerals and their chemical reactions is termed Chemical Mineralogy.
Each mineral, with few exceptions, has its definite form, by which, when in good specimens, it may be known. These forms are cubes, prisms, pyramids, etc. They are included under plane surfaces arranged in symmetrical order, according to mathematical law. These forms are called crystals. Besides these outward forms there is also a distinctive internal structure for each species. The facts of this branch of the science come under the head of Crystallographic Mineralogy.
Minerals differ in hardness, from talc at one end of the scale to the diamond at the other. Minerals differ in specific gravity, and this character, like hardness, is a most important means of distinguishing species. Minerals differ in color, transparency, luster and other optical properties. The facts and principles relating to the above characters and others of a similar nature are included in the department of Physical Mineralogy.
The detailed descriptions of individual mineral species, including their chemical, crystallographic and general physical characters, together with their occurrence, associations, uses, ete., are included under the division known as Determinative Mineralogy.
Lastly, the discussion of the methods that are used for identifying minerals forms the division known as Determinative Mineralogy.
These different branches of the subject are taken up in this site in the following order:
Molybdenum Element, Alloys and Symbols Single-roll crusher 'Fairmont' Applications Gold Mining in South Africa Breaking Mechanics: Impact, sledging, and pressure crushing in Roll Crushers Milling, Smelting and the Environment What is an Overflow Grinding Mill Mineral Outcrop Observations Technical Papers & Research Articals Mineral Processing Methods Primary and Secondary Vein Minerals - Secondary Enrichment Identifying Niobium Minerals Crusher Settings Arsenic Composition, Crystallization, Structure and Occurrence Decomposition of xanthates Picture of a Short Sluice
