Strunz classification . It is a system of classification of minerals based on their chemical composition , presented by the German mineralogist Karl Hugo Strunz 1910 – 2006 .

Summary

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• 1 Strunz
• 2 Features
• 3 Properties of minerals
• 4 Classification until the 8th edition
• 5 Ranking in the 10th edition
• 6 See also
• 7 Sources

Strunz

He served as curator of the mineral museum of the Friedrich-Wilhelms-Universität (today Humboldt University of Berlin ), Strunz was in charge of classifying the museum based on crystallochemical properties .

characteristics

The crystalline structure of a mineral is the long-range spatial arrangement of the atoms that make it up. As is known, there are 14 possible basic crystal arrangements called Bravais networks so that a crystal will present one of them.

Minerals with the same chemical composition but different crystal structure are called polymorphs; such is the case, for example, of pyrite and marcasite, whose composition is iron sulfate. Similarly, there are minerals with the same crystalline structure and different chemical composition, such as halite and galena, both with a cubic structure. Its mineralogical tables, first published in 1941 , have undergone a series of modifications, most recently in the ninth edition, published in 2001 .

Properties of minerals

The physical properties that are considered in the study of minerals are hardness , brightness, color , exfoliation and type of fracture , density and others such as fluorescence (response to ultraviolet radiation ), magnetism , radioactivity , toughness ( response to variable mechanical requests), etc.

The current system divides the minerals into nine classes, which are further divided into other subdivisions, families and groups, always following the chemical and crystallographic composition of the minerals.

Classification until the 8th edition

The classic system that still appears in many books on mineralogy divides minerals into nine classes, which in turn are divided again into various divisions, families and groups, according to the chemical composition and crystal structure of the specimens.

• Native elements Gold , Silver , Copper , Graphite , Bismuth , Arsenic
• Sulfides and sulfosalts Pyrite , Galena , Blenda , Cinnabar , Antimonite , Rejalgar
• Halide regular Halita and blue, Silvina , Fluorite , Atacamite
• Oxides and hydroxides Magnetite , Hematite , Corundum , Rutile , Goetite
• Nitrates , carbonates and borates Calcite , Dolomite , Magnesite , Aragonite , Borax
• Sulphates , chromates , molybdates and tungstates Gypsum , Anhydrite , Glaubertita , Barite , Celestina , Thenardite
• Phosphates , arsenates and vanadates Pyromorphite , Apatite , Vivianita , vanadite
• Silicates – quartz , mica , kyanite , amazonite , tourmaline , sepiolite , amphibole
• Organic substances

Ranking in the 10th edition

The classification currently established is somewhat different, dividing minerals into the following ten classes:

• 01 – Elements:
  • A – Metals and Metal Alloys
  • B – Metal carbides, silicides, nitrides and phosphides
  • C – Metalloids and non-metals
  • D – Non-metallic carbides and nitrides
• 02 – Sulfides and sulfosalts:
  • A – Metalloid alloys
  • B – Sulfides with metal, M: S> 1: 1 (mainly 2: 1)
  • C – Sulfides with metal, M: S = 1: 1 (and the like)
  • D – Sulfides with metal, M: S = 3: 4 and 2: 3
  • E – Sulfides with metal, M: S ≤ 1: 2
  • F – Sulfides of arsenic, alkalis, sulphides with halides, oxides, hydroxide, H ₂O
  • H – Sulfosalts of the SnS archetype
  • J – Sulphosalts of the PbS archetype
  • K – Sulfarsenates, Sulfantimonates
  • L – Sulfosales not classified
  • M – Oxisulfosales
• 03 – Halides:
  • A – Simple halides, without H ₂O
  • B – Simple halides, with H ₂O
  • C – Complex halides
  • D – Oxyhalides, hydroxyhalides and halides with double bonds
• 04 – Oxides and hydroxides:
  • A – Metal: Oxygen = 2.1 and 1: 1
  • B – Metal: Oxygen = 3: 4 and the like
  • C – Metal: Oxygen = 2: 3, 3: 5, and Similar
  • D – Metal: Oxygen = 1: 2 and the like
  • E – Metal: Oxygen = <1: 2
  • F – Hydroxides (without V or U)
  • G – Uranyl-hydroxides
  • H – V [5 +, 6 +] Vanadates
  • J – Arsenites, Antimonites, Bismuthites, Sulfites
  • K – Yodatos
• 05 – Carbonates and Nitrates:
  • A – Carbonates without additional anions, without H ₂O
  • B – Carbonates with additional anions, without H ₂O
  • C – Carbonates without additional anions, with H ₂O
  • D – Carbonates with additional anions, with H ₂O
  • E – Uranyl-carbonates
  • N – Nitrates
• 06 – Borates:
  • A – Monoborates
  • B – Diborates
  • C – Triborates
  • D – Tetraborates
  • E – Pentaborates
  • F – Hexaborates
  • G – Heptaborates and other megaborates
  • H – Borates not classified
• 07 – Sulfates:
  • A – Sulfates (selenates, etc.) without additional anions, without H ₂O
  • B – Sulfates (selenates, etc.) with additional anions, without H ₂O
  • C – Sulfates (selenates, etc.) without additional anions, with H ₂O
  • D – Sulfates (selenates, etc.) with additional anions, with H ₂O
  • E – Uranyl sulfates
  • F – Chromates
  • G – Molybdates, Wolframates and Niobatos
  • H – Uranium and Uranyl Molybdates and Wolframates
  • J – Thiosulfates
• 08 – Phosphates:
  • A – Phosphates, etc. without additional anions, without H ₂O
  • B – Phosphates, etc. with additional anions, without H ₂O
  • C – Phosphates without additional anions, with H ₂O
  • D – Phosphates, etc
  • E – Uranyl phosphates and arsenates
  • F – Polyphosphates, Polyarsenates, [4] -Polyvanadates
• 09 – Silicates:
  • A – Nesosilicates
  • B – Sorosilicates
  • C – Cyclosilicates
  • D – Inosilicates
  • E – Philosilicates
  • F – Tectosilicates without zeolite H ₂O
  • G – Tektosilicates with zeolite H ₂O
  • H – Silicates not classified
  • J – Germanatos
• 10 – Organic compounds:
  • A – Organic Acid Salts
  • B – Hydrocarbons
  • C – Miscellaneous organic minerals

 

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