Autor: Andrzej Kasperowicz (andy_k_at_cksr.ac.bialystok.pl)
Data: Thu 30 Jan 2003 - 15:54:23 MET
> a jak w temacie mineralow ujac rtec rodzima ? jestprzeciez plynna
> zatem definicja o mineralach jako substancjach nieorganicznych i w
> stanie stalym jej nie obejmuje a nazywana jest mineralem i o ile
> dobrze pamietam zalicza sie ja w systematyce mineralow do rodzimkow
> czy tak ? pozdrawiam Bartek
Brawo Bartku - strzal w dziesiatke z ta rtecia! Tez wydawalo mi sie, ze zalicza sie ja do mineralow, tymczasem w wiekszosci definicji mineralow mowi sie o stalych substancjach krystalicznych, a moze to jednak "tylko" mineraloid jak bursztyn, opal i ropa naftowa? Zadziwiajace, ze w tak podstawowej sprawie panuje taki balagan. Ponizej pozwole sobie zacytowac definicje mineralow z roznych encyklopedii, moze na ich podstawie ostatecznie uda nam sie sformulowac zadowalajaca wszystkich definicje.
Najciekawsze sa definicje angielskojezyczne z encyklopedii World Book i
Britannica, gdyz wskazuja wlasnie na rozne pojmowanie slowa mineral.
Odnosnie Hg, tak jak sugerowalem wyzej, Britannica nie uwaza jej za mineral:
"liquid mercury, though sometimes found in mercury ore deposits, is not
classified as a mineral either" (pelny tekst definicji zacytowalem
ponizej).
Jednakze Microsoft Encarta Encyclopedia 2002 juz zdaje sie raczej uwazac
nie tylko rtec, ale i wode za mineral:
"Mineral species are, as a rule, limited to solid substances, the only
liquids being metallic mercury and water."
No ale M$ jak sadze nie powinien byc uwazany za zrodlo rzetelnej
wiedzy... ;)
ak
Minerał
Minerał, pierwiastek, związek chemiczny bądź jednorodna mieszanina
pierwiastków lub związków, posiadające ściśle określony skład chemiczny
oraz proporcje, uporządkowaną budowę wewnętrzną (zwykle w postaci
kryształu) i zawsze występujące w stałym stanie skupienia. Stanowi
najmniejszą, niepodzielną jednostkę litosfery, utworzoną w wyniku
naturalnych procesów geologicznych lub kosmologicznych.
Powstaje na drodze krystalizacji, przyjmując, w zależności od budujących kryształ składników, określony kształt, będący odbiciem jego wewnętrznej struktury - tzw. sieci krystalicznej (Bravais'ego sieci). Struktura określa pozostałe cechy danego minerału, m.in.: łupliwość (łupliwość minerałów), twardość, barwę i połysk (połysk minerału).
Ze względu na genezę wyróżnia się: minerały pierwotne - powstające w procesie krystalizacji magmy, na drodze krystalizacji z roztworów pomagmowych (pomagmowe procesy) lub przez wydzielanie się z wód źródlanych, jeziornych i morskich, oraz minerały wtórne - powstające w wyniku przeobrażeń (w procesach wietrzenia, diagenezy lub metamorfizmu) minerałów pierwotnych.
W przyrodzie występują w postaci ogromnych zespołów, czyli skał, tworząc niekiedy w ich obrębie niewielkie, pojedyncze skupiska monomineralne (np. konkrecje, sekrecje). Zasadniczymi składnikami skał są tzw. minerały skałotwórcze, do których zalicza się nieco ponad 200 minerałów z ogólnej liczby ok. 3000 dotychczas poznanych.
minerał (ś.łc. minerale r. n. od mineralis mineralny, kopalny) miner. jednorodna substancja stała w postaci pierwiastka, związku chem. lub ich stałych roztworów powstała w skorupie ziemskiej w wyniku procesów geologicznych, gł. o budowie krystalicznej; także substancja wytworzona sztucznie, np. korund syntetyczny; m. skałotwórczy minerał, który jest jednym z gł. składników określonego typu skały.
Hasło opracowano na podstawie Słownika Wyrazów Obcych Wydawnictwa Europa, pod redakcją naukową prof. Ireny Kamińskiej-Szmaj, autorzy: Mirosław Jarosz i zespół. ISBN 83-87977-08-X. Rok wydania 2001.
Komputerowy Słownik Języka Polskiego PWN 1996
minerał m IV, D. -u, Ms. ~ale; lm M. -y
związek chemiczny, rzadziej pierwiastek chemiczny, powstały w skorupie
ziemskiej wskutek procesów geologicznych, mający określony skład
chemiczny i właściwości fizyczne, występujący przeważnie w postaci
krystalicznej; także substancja otrzymana syntetycznie w sposób
laboratoryjny lub przemysłowy (np. diament, korund)
Minerały skałotwórcze minerały tworzące skały skorupy ziemskiej,
zawierające najbardziej rozpowszechnione w niej pierwiastki chemiczne
śrdwłc.
Komputerowy Słownik Wyrazów Obcych, jw.
minerał związek chemiczny, rzadziej pierwiastek chemiczny, powstały w skorupie ziemskiej wskutek procesów geologicznych, mający określony skład chemiczny i właściwości fizyczne, występujący przeważnie w postaci krystalicznej fr. mineral (od mine; p. mina II)
World Book 2002 Deluxe
Mineral is the most common solid material found on the earth. The earth's land and oceans all rest on a layer of rock made of minerals. Rocks on the earth's surface are also made of minerals. Even soil contains tiny pieces of minerals broken from rocks. Minerals are also found on our moon and on Mercury, Venus, and Mars.
Minerals include such common substances as rock salt and pencil "lead," and such rare ones as gold, silver, and gems. There are about 3,000 kinds of minerals, but only about 100 of them are common. Most of the others are harder to find than gold.
People use minerals to make many products. For example, graphite is used for pencil leads. Other products made from minerals include cement for building, fertilizers for farming, and chemicals for manufacturing.
Many people use the term mineral for any substance taken from the earth. Such substances include coal, petroleum, natural gas, and sand--none of which is a mineral. However, these substances are commonly known as mineral resources. Certain substances in food and water, such as calcium, iron, and phosphorus, also are called minerals. But mineralogists, the scientists who study minerals, do not consider any of them minerals.
Mineralogists use the term mineral to mean a substance that has all of the four following features. (1) A mineral is found in nature. A natural diamond is a mineral, but a synthetic diamond is not. (2) A mineral has the same chemical makeup wherever it is found. Sand is not a mineral because samples from different places usually have different chemical makeups. They are mixtures. (3) The atoms of a mineral are arranged in a regular pattern, and form solid units called crystals. The calcium and phosphorus found in milk are not minerals because they are dissolved in a liquid and are not crystals. (4) With some exceptions, a mineral is made up of substances that were never alive. Coal, petroleum, and natural gas are not minerals partly because they were formed from the remains of animals and plants. In addition, coal is not a mineral because it does not have a consistent chemical makeup. Furthermore, petroleum and natural gas are not minerals because they are not solids. The exceptions- -minerals that are made up of substances that were once alive--have undergone a transformation by inorganic processes over many years. One example is calcite.
This article discusses only substances that mineralogists consider minerals. For information on coal, oil, and other products taken from the ground, see MINING with its list of Related Articles. For information on other materials that are often called minerals, see NUTRITION (Minerals) and OCEAN (Minerals).
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Encyclopedia Britannica
Mineral
naturally occurring homogeneous solid with a definite chemical
composition and a highly ordered atomic arrangement; it is usually formed
by inorganic processes. There are several thousand known mineral species,
about 100 of which constitute the major mineral components of rocks;
these are the so-called rock-forming minerals.
Mineral - any naturally occurring homogeneous solid that has a definite chemical composition and a distinctive internal crystal structure. Minerals are usually formed by inorganic processes. While this definition is applicable in most cases, there are certain notable exceptions. The term mineral is also applied to certain organic substances, such as coal, graphite, oil, and natural gas, that are obtained from the Earth for commercial use. Synthetic equivalents of various minerals, such as emeralds and diamonds, can be produced in the laboratory for experimental or commercial purposes.
Although most minerals are chemical compounds, a small number (e.g., sulfur, copper, gold) are elements. The composition of a mineral can be defined by its chemical formula, and the identity of its anionic group determines the group into which the mineral is classified. For example, the mineral halite (NaCl) is composed of two elements, sodium (Na) and chlorine (Cl), in a 1:1 ratio; its anionic group is chloride (Cl-)a halideso halite is classified as a halide. Minerals can thus be classified into the following major groups: native elements, sulfides, sulfosalts, oxides and hydroxides, halides, carbonates, nitrates, borates, sulfates, phosphates, and silicates. Silicates are the most commonly occurring minerals because silica is the most abundant constituent of the Earth's crust (about 59 percent).
A mineral crystallizes in an orderly, three-dimensional geometric form, so that it is considered to be a crystalline material. Along with its chemical composition, the crystalline structure of a mineral helps determine such physical properties as hardness, colour, and cleavage.
Minerals combine with each other to form rocks. For example, granite consists of the minerals feldspar, quartz, mica, and amphibole in varying chemical ratios. Rocks are thus distinguished from minerals by their heterogeneous composition. A mere 100 of the several thousand known types of minerals constitute the main components of rocks.
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General considerations
Definition
A mineral, which by definition must be formed through natural processes,
is distinct from the synthetic equivalents produced in the laboratory.
Man-made versions of minerals, including emeralds, sapphires, diamonds,
and other valuable gemstones, are regularly produced in industrial and
research facilities and are often nearly identical to their natural
counterparts.
By its definition as a homogeneous solid, a mineral is composed of a single solid substance of uniform composition that cannot be physically separated into simpler compounds. Homogeneity is determined relative to the scale on which it is defined. A specimen that megascopically appears homogeneous, for example, may reveal several mineral components under a microscope or upon exposure to X-ray diffraction techniques. Most rocks are composed of several different minerals; e.g., granite consists of feldspar, quartz, mica, and amphibole. In addition, gases and liquids are excluded by a strict interpretation of the above definition of a mineral. Ice, the solid state of water (H2O), is considered a mineral, but liquid water is not; liquid mercury, though sometimes found in mercury ore deposits, is not classified as a mineral either. Such substances that resemble minerals in chemistry and occurrence are dubbed mineraloids and are included in the general domain of mineralogy.
Since a mineral has a definite composition, it can be expressed by a specific chemical formula. Quartz (silicon dioxide), for instance, is rendered as SiO2, because the elements silicon (Si) and oxygen (O) are its only constituents and they invariably appear in a 1:2 ratio. The chemical makeup of most minerals is not as well defined as that of quartz, which is a pure substance. Siderite, for example, does not always occur as pure iron carbonate (FeCO3); magnesium (Mg), manganese (Mn), and, to a limited extent, calcium (Ca) may sometimes substitute for the iron. Since the amount of the replacement may vary, the composition of siderite is not fixed and ranges between certain limits, although the ratio of the metal cation to the anionic group remains fixed at 1:1. Its chemical makeup may be expressed by the general formula (Fe, Mn, Mg, Ca)CO3, which reflects the variability of the metal content.
Minerals display a highly ordered internal atomic structure that has a regular geometric form (see Figure 1). Because of this feature, minerals are classified as crystalline solids. Under favourable conditions, crystalline materials may express their ordered internal framework by a well-developed external form, often referred to as crystal form or morphology (see Figure 2). Solids that exhibit no such ordered internal arrangement are termed amorphous. Many amorphous natural solids, such as glass, are categorized as mineraloids.
Traditionally, minerals have been described as resulting exclusively from inorganic processes; however, current mineralogic practice often includes as minerals those compounds that are organically produced but satisfy all other mineral requirements. Aragonite (CaCO3) is an example of an inorganically formed mineral that also has an organically produced, yet otherwise identical, counterpart; the shell (and the pearl, if it is present) of an oyster is composed to a large extent of organically formed aragonite. Minerals also are produced by the human body: hydroxylapatite [Ca5(PO4)3(OH)] is the chief component of bones and teeth, and calculi are concretions of mineral substances found in the urinary system.
Nomenclature
While minerals are classified in a logical manner according to their
major anionic (negatively charged) chemical constituents into groups such
as oxides, silicates, and nitrates, they are named in a far less
scientific or consistent way. Names may be assigned to reflect a physical
or chemical property, such as colour, or they may be derived from various
subjects deemed appropriate, as, for example, a locality, public figure,
or mineralogist. Some examples of mineral names and their derivations
follow: albite (NaAlSi3O8) is from the Latin word (albus) for white in
reference to its colour; goethite (FeO × OH) is in honour of Johann
Wolfgang von Goethe, the German poet; manganite (MnO × OH) reflects the
mineral's composition; franklinite (ZnFe2O4) is named after Franklin,
N.J., U.S., the site of its occurrence as the dominant zinc (Zn) mineral;
and sillimanite (Al2SiO4) is in honour of the American chemist Benjamin
Silliman. Since 1960, an international committee of nomenclature has
reviewed descriptions of new minerals and proposals for new mineral names
and has attempted to remove inconsistencies.
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Microsoft Encarta Encyclopedia 2002
Mineral (chemistry), in general, any naturally occurring chemical element or compound, but in mineralogy and geology, chemical elements and compounds that have been formed through inorganic processes. Petroleum and coal, which are formed by the decomposition of organic matter, are not minerals in the strict sense. More than 3000 mineral species are known, most of which are characterized by definite chemical composition, crystalline structure, and physical properties. They are classified primarily by chemical composition, crystal class, hardness, and appearance (color, luster, and opacity). Mineral species are, as a rule, limited to solid substances, the only liquids being metallic mercury and water. All the rocks forming the earth's crust consist of minerals. Metalliferous minerals of economic value, which are mined for their metals, are known as ores. See Crystal.
Random House Websters Electronic Dictionary 1992
min-er-al (min'uhr uhl, min'ruhl) n.
Collins English Dictionary 1992
mineral (`mnrl, `mnrl)
1. any of a class of naturally occurring solid inorganic substances with
a characteristic crystalline form and a homogeneous chemical composition
2. any inorganic matter 3. any substance obtained by mining, esp. a metal ore 4. (often pl) Brit. short for mineral water 5. Brit. a soft drink containing carbonated water and flavourings. Usual U.S. word: soda 5. of, relating to, containing, or resembling minerals[C15: from MedievalLatin minerťle (n.), from mineralis (adj.); related to minera mine, ore, of uncertain origin]
The American Heritage Dictionary 1993
min˙er˙al (mąn r- l) n. 1. A naturally occurring, homogeneous inorganic solid substance having a definite chemical composition and characteristic crystalline structure, color, and hardness. 2. Any of various natural
substances, as: a. An element, such as gold or silver. b. An organic derivative, such as coal or petroleum. c. A substance, such as stone, sand, salt, or coal, that is extracted or obtained from the ground orwater and used in economic activities. 3. A substance that is neither animal nor vegetable; inorganic matter. 4. An inorganic element, such as calcium, iron, potassium, sodium, or zinc, that is essential to the nutrition of human beings, animals, and plants. 5. An ore. 6. minerals. Chiefly British. Mineral water. --min˙er˙al adj. 1. Of or relating to minerals: a mineral deposit. 2. Impregnated with minerals. [Middle English, from Medieval Latin minerłle, from neuter of minerłlis, pertaining to mines, from Old French miniere, mine, from mine. See MINE1.]
A teraz mineraloid:
Multimedialna Encyklopedia Powszechna - edycja 2002
Mineraloid, skupienie w obrębie skorupy ziemskiej określonych substancji chemicznych, charakteryzujące się niejednorodnością składu chemicznego oraz nieokreśloną strukturą budowy wewnętrznej. Najczęściej jest to zwarta grupa różnych minerałów nie tworzących określonej struktury krystalicznej (np. limonit, szkliwo wulkaniczne) lub kompleks związków chemicznych, nie będących minerałami, tworzących mieszaniny o różnych proporcjach (np. ropa naftowa).
The End :)
ak
To archiwum zostało wygenerowane przez hypermail 2.1.7 : Thu 04 Mar 2004 - 21:31:38 MET