Mineralogy

Mineralogy

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Encyclopedia
Mineralogy is the study of chemistry
Chemistry
Chemistry is the science of matter, especially its chemical reactions, but also its composition, structure and properties. Chemistry is concerned with atoms and their interactions with other atoms, and particularly with the properties of chemical bonds....

, crystal structure
Crystal structure
In mineralogy and crystallography, crystal structure is a unique arrangement of atoms or molecules in a crystalline liquid or solid. A crystal structure is composed of a pattern, a set of atoms arranged in a particular way, and a lattice exhibiting long-range order and symmetry...

, and physical (including optical
Optical mineralogy
Optical mineralogy is the study of minerals and rocks by measuring their optical properties. Most commonly, rock and mineral samples are prepared as thin sections or grain mounts for study in the laboratory with a petrographic microscope...

) properties of mineral
Mineral
A mineral is a naturally occurring solid chemical substance formed through biogeochemical processes, having characteristic chemical composition, highly ordered atomic structure, and specific physical properties. By comparison, a rock is an aggregate of minerals and/or mineraloids and does not...

s. Specific studies within mineralogy include the processes of mineral origin and formation, classification
Biological classification
Biological classification, or scientific classification in biology, is a method to group and categorize organisms by biological type, such as genus or species. Biological classification is part of scientific taxonomy....

 of minerals, their geographical distribution, as well as their utilization.

History



Early writing on mineralogy, especially on gemstones, comes from ancient Babylonia
Babylonia
Babylonia was an ancient cultural region in central-southern Mesopotamia , with Babylon as its capital. Babylonia emerged as a major power when Hammurabi Babylonia was an ancient cultural region in central-southern Mesopotamia (present-day Iraq), with Babylon as its capital. Babylonia emerged as...

, the ancient Greco-Roman world, ancient and medieval China
History of China
Chinese civilization originated in various regional centers along both the Yellow River and the Yangtze River valleys in the Neolithic era, but the Yellow River is said to be the Cradle of Chinese Civilization. With thousands of years of continuous history, China is one of the world's oldest...

, and Sanskrit
Sanskrit
Sanskrit , is a historical Indo-Aryan language and the primary liturgical language of Hinduism, Jainism and Buddhism.Buddhism: besides Pali, see Buddhist Hybrid Sanskrit Today, it is listed as one of the 22 scheduled languages of India and is an official language of the state of Uttarakhand...

 texts from ancient India
History of India
The history of India begins with evidence of human activity of Homo sapiens as long as 75,000 years ago, or with earlier hominids including Homo erectus from about 500,000 years ago. The Indus Valley Civilization, which spread and flourished in the northwestern part of the Indian subcontinent from...

 and the ancient Islamic World. Books on the subject included the Naturalis Historia
Naturalis Historia
The Natural History is an encyclopedia published circa AD 77–79 by Pliny the Elder. It is one of the largest single works to have survived from the Roman Empire to the modern day and purports to cover the entire field of ancient knowledge, based on the best authorities available to Pliny...

 of Pliny the Elder
Pliny the Elder
Gaius Plinius Secundus , better known as Pliny the Elder, was a Roman author, naturalist, and natural philosopher, as well as naval and army commander of the early Roman Empire, and personal friend of the emperor Vespasian...

, which not only described many different minerals but also explained many of their properties, and Kitab al Jawahir (Book of Precious Stones) by Muslim scientist Al Biruni. The German Renaissance
German Renaissance
The German Renaissance, part of the Northern Renaissance, was a cultural and artistic movement that spread among German thinkers in the 15th and 16th centuries, which originated from the Italian Renaissance in Italy...

 specialist Georgius Agricola wrote works such as De re metallica
De re metallica
De re metallica is a book cataloguing the state of the art of mining, refining, and smelting metals, published in 1556. The author was Georg Bauer, whose pen name was the Latinized Georgius Agricola...

(On Metals, 1556) and De Natura Fossilium
De Natura Fossilium
De Natura Fossilium is a scientific text written by George Bauer also known as Georgius Agricola, first published in 1546. The book represents the first scientific attempt to categorize minerals, rocks and sediments since the publication of Pliny's Natural History...

(On the Nature of Rocks, 1546) which begin the scientific approach to the subject. Systematic scientific studies of minerals and rocks developed in post-Renaissance
Renaissance
The Renaissance was a cultural movement that spanned roughly the 14th to the 17th century, beginning in Italy in the Late Middle Ages and later spreading to the rest of Europe. The term is also used more loosely to refer to the historical era, but since the changes of the Renaissance were not...

 Europe. The modern study of mineralogy was founded on the principles of crystallography
Crystallography
Crystallography is the experimental science of the arrangement of atoms in solids. The word "crystallography" derives from the Greek words crystallon = cold drop / frozen drop, with its meaning extending to all solids with some degree of transparency, and grapho = write.Before the development of...

 (the origins of geometric crystallography, itself, can be traced back to the mineralogy practiced in the eighteenth and nineteenth centuries) and to the microscopic
Microscopic
The microscopic scale is the scale of size or length used to describe objects smaller than those that can easily be seen by the naked eye and which require a lens or microscope to see them clearly.-History:...

 study of rock sections with the invention of the microscope
Microscope
A microscope is an instrument used to see objects that are too small for the naked eye. The science of investigating small objects using such an instrument is called microscopy...

 in the 17th century.

Modern mineralogy



Historically, mineralogy was heavily concerned with taxonomy
Taxonomy
Taxonomy is the science of identifying and naming species, and arranging them into a classification. The field of taxonomy, sometimes referred to as "biological taxonomy", revolves around the description and use of taxonomic units, known as taxa...

 of the rock-forming minerals; to this end, the International Mineralogical Association
International Mineralogical Association
The International Mineralogical Association is an international group of 38 national societies. The goal is to promote the science of mineralogy and to standardize the nomenclature of the 4000 plus known mineral species...

 is an organization whose members represent mineralogists in individual countries. Its activities include managing the naming of minerals (via the Commission of New Minerals and Mineral Names), location of known minerals, etc. As of 2004 there are over 4,000 species of mineral recognized by the IMA. Of these, perhaps 150 can be called "common," another 50 are "occasional," and the rest are "rare" to "extremely rare."

More recently, driven by advances in experimental technique (such as neutron diffraction
Neutron diffraction
Neutron diffraction or elastic neutron scattering is the application of neutron scattering to the determination of the atomic and/or magnetic structure of a material: A sample to be examined is placed in a beam of thermal or cold neutrons to obtain a diffraction pattern that provides information of...

) and available computational power, the latter of which has enabled extremely accurate atomic-scale simulations of the behaviour of crystals, the science has branched out to consider more general problems in the fields of inorganic chemistry
Inorganic chemistry
Inorganic chemistry is the branch of chemistry concerned with the properties and behavior of inorganic compounds. This field covers all chemical compounds except the myriad organic compounds , which are the subjects of organic chemistry...

 and solid-state physics
Solid-state physics
Solid-state physics is the study of rigid matter, or solids, through methods such as quantum mechanics, crystallography, electromagnetism, and metallurgy. It is the largest branch of condensed matter physics. Solid-state physics studies how the large-scale properties of solid materials result from...

. It, however, retains a focus on the crystal structures commonly encountered in rock-forming minerals (such as the perovskite
Perovskite
A perovskite structure is any material with the same type of crystal structure as calcium titanium oxide , known as the perovskite structure, or XIIA2+VIB4+X2−3 with the oxygen in the face centers. Perovskites take their name from this compound, which was first discovered in the Ural mountains of...

s, clay minerals
Clay minerals
Clay minerals are hydrous aluminium phyllosilicates, sometimes with variable amounts of iron, magnesium, alkali metals, alkaline earths, and other cations. Clays have structures similar to the micas and therefore form flat hexagonal sheets. Clay minerals are common weathering products and low...

 and framework silicates). In particular, the field has made great advances in the understanding of the relationship between the atomic-scale structure of minerals and their function; in nature, prominent examples would be accurate measurement and prediction of the elastic properties of minerals, which has led to new insight into seismological
Seismology
Seismology is the scientific study of earthquakes and the propagation of elastic waves through the Earth or through other planet-like bodies. The field also includes studies of earthquake effects, such as tsunamis as well as diverse seismic sources such as volcanic, tectonic, oceanic,...

 behaviour of rocks and depth-related discontinuities in seismograms of the Earth's mantle. To this end, in their focus on the connection between atomic-scale phenomena and macroscopic properties, the mineral sciences (as they are now commonly known) display perhaps more of an overlap with materials science
Materials science
Materials science is an interdisciplinary field applying the properties of matter to various areas of science and engineering. This scientific field investigates the relationship between the structure of materials at atomic or molecular scales and their macroscopic properties. It incorporates...

 than any other discipline.

Physical mineralogy


Physical mineralogy is the specific focus on physical attributes of minerals. Description of physical attributes is the simplest way to identify, classify, and categorize minerals, and they include:
  • crystal structure
    Crystal structure
    In mineralogy and crystallography, crystal structure is a unique arrangement of atoms or molecules in a crystalline liquid or solid. A crystal structure is composed of a pattern, a set of atoms arranged in a particular way, and a lattice exhibiting long-range order and symmetry...

  • crystal habit
    Crystal habit
    Crystal habit is an overall description of the visible external shape of a mineral. This description can apply to an individual crystal or an assembly of crystals or aggregates....

  • twinning
    Crystal twinning
    Crystal twinning occurs when two separate crystals share some of the same crystal lattice points in a symmetrical manner. The result is an intergrowth of two separate crystals in a variety of specific configurations. A twin boundary or composition surface separates the two crystals....

  • cleavage
    Cleavage (crystal)
    Cleavage, in mineralogy, is the tendency of crystalline materials to split along definite crystallographic structural planes. These planes of relative weakness are a result of the regular locations of atoms and ions in the crystal, which create smooth repeating surfaces that are visible both in the...

  • luster
    Lustre (mineralogy)
    Lustre is a description of the way light interacts with the surface of a crystal, rock, or mineral. The word lustre traces its origins back to the Latin word lux, meaning "light", and generally implies radiance, gloss, or brilliance....

  • color
  • streak
    Streak (mineralogy)
    The streak of a mineral is the color of the powder produced when it is dragged across an unweathered surface. Unlike the apparent color of a mineral, which for most minerals can vary considerably, the trail of finely ground powder generally has a more consistent characteristic color, and is thus...

  • hardness
  • specific gravity
    Specific gravity
    Specific gravity is the ratio of the density of a substance to the density of a reference substance. Apparent specific gravity is the ratio of the weight of a volume of the substance to the weight of an equal volume of the reference substance. The reference substance is nearly always water for...


Chemical mineralogy


Chemical mineralogy focuses on the chemical composition of minerals in order to identify, classify, and categorize them, as well as a means to find beneficial uses from them. There are a few minerals which are classified as whole elements, including sulfur
Sulfur
Sulfur or sulphur is the chemical element with atomic number 16. In the periodic table it is represented by the symbol S. It is an abundant, multivalent non-metal. Under normal conditions, sulfur atoms form cyclic octatomic molecules with chemical formula S8. Elemental sulfur is a bright yellow...

, copper
Copper
Copper is a chemical element with the symbol Cu and atomic number 29. It is a ductile metal with very high thermal and electrical conductivity. Pure copper is soft and malleable; an exposed surface has a reddish-orange tarnish...

, silver
Silver
Silver is a metallic chemical element with the chemical symbol Ag and atomic number 47. A soft, white, lustrous transition metal, it has the highest electrical conductivity of any element and the highest thermal conductivity of any metal...

, and gold
Gold
Gold is a chemical element with the symbol Au and an atomic number of 79. Gold is a dense, soft, shiny, malleable and ductile metal. Pure gold has a bright yellow color and luster traditionally considered attractive, which it maintains without oxidizing in air or water. Chemically, gold is a...

, yet the vast majority of minerals are chemical compounds, some more complex than others. In terms of major chemical divisions of minerals, most are placed within the isomorphous
Isomorphism
In abstract algebra, an isomorphism is a mapping between objects that shows a relationship between two properties or operations.  If there exists an isomorphism between two structures, the two structures are said to be isomorphic.  In a certain sense, isomorphic structures are...

 groups, which are based on analogous chemical composition and similar crystal forms. A good example of isomorphism classification would be the calcite
Calcite
Calcite is a carbonate mineral and the most stable polymorph of calcium carbonate . The other polymorphs are the minerals aragonite and vaterite. Aragonite will change to calcite at 380-470°C, and vaterite is even less stable.-Properties:...

 group, containing the minerals calcite, magnesite
Magnesite
Magnesite is magnesium carbonate, MgCO3. Iron substitutes for magnesium with a complete solution series with siderite, FeCO3. Calcium, manganese, cobalt, and nickel may also occur in small amounts...

, siderite
Siderite
Siderite is a mineral composed of iron carbonate FeCO3. It takes its name from the Greek word σίδηρος sideros, “iron”. It is a valuable iron mineral, since it is 48% iron and contains no sulfur or phosphorus...

, rhodochrosite
Rhodochrosite
Rhodochrosite is a manganese carbonate mineral with chemical composition MnCO3. In its pure form, it is typically a rose-red color, but impure specimens can be shades of pink to pale brown. The streak is white. Its Mohs hardness varies between 3.5 and 4. Its specific gravity is 3.5 to 3.7. It...

, and smithsonite
Smithsonite
Smithsonite, or zinc spar, is zinc carbonate , a mineral ore of zinc. Historically, smithsonite was identified with hemimorphite before it was realised that they were two distinct minerals. The two minerals are very similar in appearance and the term calamine has been used for both, leading to some...

.

Biomineralogy


Biomineralogy is a cross-over field between mineralogy, paleontology
Paleontology
Paleontology "old, ancient", ὄν, ὀντ- "being, creature", and λόγος "speech, thought") is the study of prehistoric life. It includes the study of fossils to determine organisms' evolution and interactions with each other and their environments...

 and biology
Biology
Biology is a natural science concerned with the study of life and living organisms, including their structure, function, growth, origin, evolution, distribution, and taxonomy. Biology is a vast subject containing many subdivisions, topics, and disciplines...

. It is the study of how plants and animals stabilize minerals under biological control, and the sequencing of mineral replacement of those minerals after deposition. It uses techniques from chemical mineralogy, especially isotopic studies, to determine such things as growth forms in living plants and animals as well as things like the original mineral content of fossils.

Optical mineralogy


Optical
Optics
Optics is the branch of physics which involves the behavior and properties of light, including its interactions with matter and the construction of instruments that use or detect it. Optics usually describes the behavior of visible, ultraviolet, and infrared light...

 mineralogy is a specific focus of mineralogy that applies sources of light as a means to identify and classify minerals. All minerals which are not part of the cubic system
Cubic crystal system
In crystallography, the cubic crystal system is a crystal system where the unit cell is in the shape of a cube. This is one of the most common and simplest shapes found in crystals and minerals....

 are double refracting, where ordinary light passing through them is broken up into two plane polarized rays
Ray (optics)
In optics, a ray is an idealized narrow beam of light. Rays are used to model the propagation of light through an optical system, by dividing the real light field up into discrete rays that can be computationally propagated through the system by the techniques of ray tracing. This allows even very...

 that travel at different velocities and refracted at different angle
Angle
In geometry, an angle is the figure formed by two rays sharing a common endpoint, called the vertex of the angle.Angles are usually presumed to be in a Euclidean plane with the circle taken for standard with regard to direction. In fact, an angle is frequently viewed as a measure of an circular arc...

s. Mineral substances belonging to the cubic system pertain only one index of refraction. Hexagonal
Hexagonal crystal system
In crystallography, the hexagonal crystal system is one of the 7 crystal systems, the hexagonal lattice system is one of the 7 lattice systems, and the hexagonal crystal family is one of the 6 crystal families...

 and tetragonal mineral substances have two indices, while orthorhombic, monoclinic, and triclinic substances have three indices of refraction. With opaque
Opacity (optics)
Opacity is the measure of impenetrability to electromagnetic or other kinds of radiation, especially visible light. In radiative transfer, it describes the absorption and scattering of radiation in a medium, such as a plasma, dielectric, shielding material, glass, etc...

 ore minerals, reflected light from a microscope is needed for identification.

Crystal structure



X-ray
X-ray
X-radiation is a form of electromagnetic radiation. X-rays have a wavelength in the range of 0.01 to 10 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz and energies in the range 120 eV to 120 keV. They are shorter in wavelength than UV rays and longer than gamma...

s are used to determine the atom
Atom
The atom is a basic unit of matter that consists of a dense central nucleus surrounded by a cloud of negatively charged electrons. The atomic nucleus contains a mix of positively charged protons and electrically neutral neutrons...

ic arrangements of minerals and so to identify and classify them. The arrangements of atoms define the crystal structures of the minerals. Some very fine-grained minerals, such as clay
Clay
Clay is a general term including many combinations of one or more clay minerals with traces of metal oxides and organic matter. Geologic clay deposits are mostly composed of phyllosilicate minerals containing variable amounts of water trapped in the mineral structure.- Formation :Clay minerals...

s, commonly can be identified most readily by their crystal structures. The structure of a mineral also offers a precise way of establishing isomorphism. With knowledge of atomic arrangements and compositions, one may deduce why minerals have specific physical properties, and one may calculate how those properties change with pressure and temperature.

Formation environments


The environments of mineral formation and growth are highly varied, ranging from slow crystallization at the high temperature and pressures of igneous melts
Magma
Magma is a mixture of molten rock, volatiles and solids that is found beneath the surface of the Earth, and is expected to exist on other terrestrial planets. Besides molten rock, magma may also contain suspended crystals and dissolved gas and sometimes also gas bubbles. Magma often collects in...

 deep within the Earth's crust
Crust (geology)
In geology, the crust is the outermost solid shell of a rocky planet or natural satellite, which is chemically distinct from the underlying mantle...

 to the low temperature precipitation from a saline brine at the Earth's surface.

Various possible methods of formation include:
  • sublimation from volcanic gases
  • deposition from aqueous solution
    Aqueous solution
    An aqueous solution is a solution in which the solvent is water. It is usually shown in chemical equations by appending aq to the relevant formula, such as NaCl. The word aqueous means pertaining to, related to, similar to, or dissolved in water...

    s and hydrothermal brine
    Brine
    Brine is water, saturated or nearly saturated with salt .Brine is used to preserve vegetables, fruit, fish, and meat, in a process known as brining . Brine is also commonly used to age Halloumi and Feta cheeses, or for pickling foodstuffs, as a means of preserving them...

    s
  • crystallization from an igneous magma
    Magma
    Magma is a mixture of molten rock, volatiles and solids that is found beneath the surface of the Earth, and is expected to exist on other terrestrial planets. Besides molten rock, magma may also contain suspended crystals and dissolved gas and sometimes also gas bubbles. Magma often collects in...

     or lava
    Lava
    Lava refers both to molten rock expelled by a volcano during an eruption and the resulting rock after solidification and cooling. This molten rock is formed in the interior of some planets, including Earth, and some of their satellites. When first erupted from a volcanic vent, lava is a liquid at...

  • recrystallization due to metamorphic
    Metamorphism
    Metamorphism is the solid-state recrystallization of pre-existing rocks due to changes in physical and chemical conditions, primarily heat, pressure, and the introduction of chemically active fluids. Mineralogical, chemical and crystallographic changes can occur during this process...

     processes and metasomatism
    Metasomatism
    Metasomatism is the chemical alteration of a rock by hydrothermal and other fluids.Metasomatism can occur via the action of hydrothermal fluids from an igneous or metamorphic source. In the igneous environment, metasomatism creates skarns, greisen, and may affect hornfels in the contact...

  • crystallization during diagenesis
    Diagenesis
    In geology and oceanography, diagenesis is any chemical, physical, or biological change undergone by a sediment after its initial deposition and during and after its lithification, exclusive of surface alteration and metamorphism. These changes happen at relatively low temperatures and pressures...

     of sediments
  • formation by oxidation and weathering
    Weathering
    Weathering is the breaking down of rocks, soils and minerals as well as artificial materials through contact with the Earth's atmosphere, biota and waters...

     of rocks exposed to the atmosphere
    Earth's atmosphere
    The atmosphere of Earth is a layer of gases surrounding the planet Earth that is retained by Earth's gravity. The atmosphere protects life on Earth by absorbing ultraviolet solar radiation, warming the surface through heat retention , and reducing temperature extremes between day and night...

     or within the soil
    Soil
    Soil is a natural body consisting of layers of mineral constituents of variable thicknesses, which differ from the parent materials in their morphological, physical, chemical, and mineralogical characteristics...

     environment.

Descriptive mineralogy



Descriptive mineralogy summarizes results of studies performed on mineral substances. It is the scholarly and scientific method of recording the identification, classification, and categorization of minerals, their properties, and their uses. Classifications for descriptive mineralogy includes:
  • native elements
  • sulfides
    Sulfide mineral
    The sulfide minerals are a class of minerals containing sulfide as the major anion. Some sulfide minerals are economically important as metal ores. The sulfide class also includes the selenides, the tellurides, the arsenides, the antimonides, the bismuthinides, the sulfarsenides and the sulfosalts...

  • oxides and hydroxides
  • halides
  • carbonates, nitrates and borates
    Carbonate minerals
    Carbonate minerals are those minerals containing the carbonate ion: CO32-.-Anhydrous carbonates:*Calcite group: Trigonal**Calcite CaCO3**Gaspeite CO3**Magnesite MgCO3**Otavite CdCO3**Rhodochrosite MnCO3**Siderite FeCO3**Smithsonite ZnCO3...

  • sulfates, chromates, molybdates and tungstates
  • phosphates, arsenates and vanadates
  • silicates
    Silicate minerals
    The silicate minerals make up the largest and most important class of rock-forming minerals, constituting approximately 90 percent of the crust of the Earth. They are classified based on the structure of their silicate group...

  • organic minerals

Determinative mineralogy


Determinative mineralogy is the actual scientific process of identifying minerals, through data gathering and conclusion. When new minerals are discovered, a standard procedure of scientific analysis is followed, including measures to identify a mineral's formula, its crystallographic data, its optical data, as well as the general physical attributes determined and listed.

Uses


Minerals are essential to various needs within human society, such as minerals used as ore
Ore
An ore is a type of rock that contains minerals with important elements including metals. The ores are extracted through mining; these are then refined to extract the valuable element....

s for essential components of metal products used in various commodities and machinery, essential components to building materials such as limestone
Limestone
Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera....

, marble
Marble
Marble is a metamorphic rock composed of recrystallized carbonate minerals, most commonly calcite or dolomite.Geologists use the term "marble" to refer to metamorphosed limestone; however stonemasons use the term more broadly to encompass unmetamorphosed limestone.Marble is commonly used for...

, granite
Granite
Granite is a common and widely occurring type of intrusive, felsic, igneous rock. Granite usually has a medium- to coarse-grained texture. Occasionally some individual crystals are larger than the groundmass, in which case the texture is known as porphyritic. A granitic rock with a porphyritic...

, gravel
Gravel
Gravel is composed of unconsolidated rock fragments that have a general particle size range and include size classes from granule- to boulder-sized fragments. Gravel can be sub-categorized into granule and cobble...

, glass
Glass
Glass is an amorphous solid material. Glasses are typically brittle and optically transparent.The most familiar type of glass, used for centuries in windows and drinking vessels, is soda-lime glass, composed of about 75% silica plus Na2O, CaO, and several minor additives...

, plaster
Plaster
Plaster is a building material used for coating walls and ceilings. Plaster starts as a dry powder similar to mortar or cement and like those materials it is mixed with water to form a paste which liberates heat and then hardens. Unlike mortar and cement, plaster remains quite soft after setting,...

, cement
Cement
In the most general sense of the word, a cement is a binder, a substance that sets and hardens independently, and can bind other materials together. The word "cement" traces to the Romans, who used the term opus caementicium to describe masonry resembling modern concrete that was made from crushed...

, etc. Minerals are also used in fertilizer
Fertilizer
Fertilizer is any organic or inorganic material of natural or synthetic origin that is added to a soil to supply one or more plant nutrients essential to the growth of plants. A recent assessment found that about 40 to 60% of crop yields are attributable to commercial fertilizer use...

s to enrich the growth of agricultural crops.

Collecting


Mineral collecting
Mineral collecting
Mineral collecting is the hobby of systematically collecting, identifying and displaying mineral specimens. Mineral collecting can also be a part of the profession of mineralogy and allied geologic specialties.-Motivations:...

 is also a recreational study and collection hobby
Hobby
A hobby is a regular activity or interest that is undertaken for pleasure, typically done during one's leisure time.- Etymology :A hobby horse is a wooden or wickerwork toy made to be ridden just like a real horse...

, with clubs and societies representing the field. Museums, such as the Smithsonian National Museum of Natural History Hall of Geology, Gems, and Minerals and the Natural History Museum of Los Angeles County
Natural History Museum of Los Angeles County
The Natural History Museum of Los Angeles County opened in Exposition Park, Los Angeles, California, USA in 1913 as the Museum of History, Science, and Art. The moving force behind it was a museum association founded in 1910. Its distinctive main building, with fitted marble walls and domed and...

, have popular collections of mineral specimens on permanent display.

External links