A big encyclopedia "Minerals guide: Geology toolkit" is a complete free handbook of terminology which covers the most important terms and concepts. That allows geologists and hobbyists to examine and explore minerals rocks gemstones and crystals features.

Mineralogy is a subject of geology specializing in the scientific study of the chemistry crystal structure and physical properties of minerals and mineralized artifacts. Specific studies within mineralogy include the processes of mineral origin and formation classification of minerals their geographical distribution as well as their utilization.

An initial step in identifying a mineral is to examine its physical properties many of which can be measured on a hand sample. These can be classified into density (often given as specific gravity); measures of mechanical cohesion (hardness tenacity cleavage fracture parting); macroscopic visual properties (luster color streak luminescence diaphaneity); magnetic and electric properties; radioactivity and solubility in hydrogen chloride

A crystal or crystalline solid is a solid material whose constituents (such as atoms molecules or ions) are arranged in a highly ordered microscopic structure forming a crystal lattice that extends in all directions. In addition macroscopic single crystals are usually identifiable by their geometrical shape consisting of flat faces with specific characteristic orientations. The scientific study of crystals and crystal formation is known as crystallography. The process of crystal formation via mechanisms of crystal growth is called crystallization or solidification.

Crystallography is the experimental science of determining the arrangement of atoms in crystalline solids. Crystallography is a fundamental subject in the fields of materials science and solid-state physics (condensed matter physics). In crystallography crystal structure is a description of the ordered arrangement of atoms ions or molecules in a crystalline material. Ordered structures occur from the intrinsic nature of the constituent particles to form symmetric patterns that repeat along the principal directions of three-dimensional space in matter.

A few minerals are chemical elements including sulfur copper silver and gold but the vast majority are compounds. The classical method for identifying composition is wet chemical analysis which involves dissolving a mineral in an acid.

A mineraloid is a naturally occurring mineral-like substance that does not demonstrate crystallinity. Mineraloids possess chemical compositions that vary beyond the generally accepted ranges for specific minerals.

A gemstone (also called a gem jewel precious stone or semi-precious stone) is a piece of crystal which in cut and polished form is used to make jewelry or other adornments. Most gemstones are hard but some soft minerals are used in jewelry because of their luster or other physical properties that have aesthetic value. Rarity is another characteristic that lends value to a gemstone.

Gold is a chemical element with the symbol Au (from Latin aurum 'gold') and atomic number 79. This makes it one of the higher–atomic-number elements that occur naturally. It is a bright slightly orange-yellow dense soft malleable and ductile metal in pure form.

There are approximately 4000 different stones and each of them has a unique set of physical properties. These include: color streak hardness luster diaphaneity specific gravity cleavage fracture magnetism solubility and many more.

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