ClassicGems.net

Mineral Classifications

Minerals can be organized, mainly according to their chemistry, into the following classes:

Native Elements Class The Metals and their alloys and the Nonmetals.
Sulfides Class: Sulfides, Selenides, Tellurides, Arsenides, Antimonides, Bismuthinides, Sulfosalts.
Oxides and Hydroxides Class: Oxides, Hydroxides.
Halides Class: Fluorides, Chlorides, Iodides.
Carbonates Class: Carbonates, Borates, Nitrates, Rare Earth Carbonates.
Sulfates Class: Sulfates, Sulfites, Chromates, Molybdates, Selenates, Selenites, Tellurates, Tellurites, Tungstates
Phosphates Class: Phosphates, Arsenates, Vanadates, Antimonates.
Silicates Class: (the largest class) Nesosilicates, Sorosilicates, Cyclosilicates, Inosilicates, Phyllosilicates, Tektosilicates, Unclassified Silicates
Organics Class: "Minerals" composed of organic chemicals
 

More information on each of the Mineral Classifications:

Native Elements Class: The Metals and their alloys and the Nonmetals.
Examples: Aluminum, Antimony, Arsenic, Copper, Diamond, Gold, Graphite, Iron, Lead, Mercury, Nickel, Platinum, Silver, Tellurium, Tin, Titanium, Zinc.
 
Sulfides Class: Sulfides, Selenides, Tellurides, Arsenides, Antimonides, Bismuthinides, Sulfosalts.
Most major ores of important metals such as copper, lead and silver are sulfides. Most sulfides are metallic, opaque, soft to average in hardness, have high densities, and an igneous origin. But, there are a few vitreous and transparent members such as Cinnabar, Orpiment and Realgar.

   Subclass: Sulfides
   Examples: Cinnabar, Galena, Marcasite, Millerite, Orpiment, Pyrite, Realgar, Sphalerite, Stibnite.

   Subclass: Sulfosalts:
   Examples: Proustite, Pyrargarite, Tetrahedrite.
 
Halides Class: Fluorides, Chlorides, Iodides.
The halides are a group of minerals whose principle anions are halogens.
Examples: Boleite, Carnallite, Fluorite, Halite, Sylvite, Villiaumite.
 
Oxides Class: Oxides, Hydroxides.
The oxide class of minerals is a very diverse class. It includes minerals that are quite hard (corundum) and some that are quite soft such as cuprite. It has metallic minerals such as hematite and gemstones such as corundum, chrysoberyl and spinel.
Examples: Anatase, Bixbyite, Brookite, Chrysoberyl, Corundum (Ruby, Sapphire), Cuprite, Hematite, Pyrochlore Groupe (Betafite, Microlite, Pyrochlore), Rutile Group (Cassiterite, Pyrolusite, Rutile), Senarmontite, Spinel Group (Chromite, Franklinite, Gahnite, Magnetite, Spinel), Taaffeite, Vallentinite, Zincite

   Subclass: Hydroxides
   Examples: Brucite, Goethite, Manganite.
 
Carbonates Class: Carbonates, Borates, Nitrates, Rare Earth Carbonates.
Typical carbonates are transparent, lightly colored, average to above average in density, soft with good to perfect cleavage, and tend to originate in sedimentary and oxidizing environments with the exception of carbonatite igneous intrusions.

Examples: Azurite, Aragonite Group (Aragonite, Cerussite, Strontianite, Witherite), Calcite Group (Calcite, Gaspeite, Magnesite, Rhodochrosite, Siderite, Smithsonite), Dolomite, Malachite, Stitchtite, Weloganite.

   Subclass: Borates
   Examples: Borax, Colemanite, Howlite, Kernite, Ulexite.

   Subclass: Rare Earth Carbonates
   Examples: Bastnasite, Burbankite, Parisite.
 
Sulfates Class: Sulfates, Sulfites, Chromates, Molybdates, Selenates, Selenites, Tellurates, Tellurites, Tungstates (or the Wolframates).
The typical Sulfate Class mineral is vitreous, average to above average in density, average in hardness and are originally formed in veins, oxidation zones, contact metamorphic zones and in evaporite deposits.

Examples: Anhydrite, Barite Group (Anglesite, Barite, Celestite), Caledonite, Creedite, Glauberite, Goetite, Gypsum (& Alabaster), Hanksite, Thaumasite.

   Subclass: Chromates
   Examples: Crocoite.

   Subclass: Molybdates
   Examples: Powellite, Wulfenite.

   Subclass: Tungstates
   Examples: Hubnerite, Scheelite, Wolframite.
 
Phosphates Class: Phosphates, Arsenates, Vanadates, Antimonates.
The typical phosphate is vitreous to dull, often strongly colored, above average in density, average in hardness (4-7) and low in index of refraction unless ions such as lead are present.

Examples: Amblygonite, Anapatite, Apatite Group (Apatite, Mimetite, Pyromorphite, Vinadinite), Augelite, Beryllonite, Brazilianite, Eosphorite, Herderite, Lazulite, Ludlamite, Monazite, Montbrasite, Phosphophyllite, Purpurite, Triphylite, Turquoise, Vivianite, Xenotime.

   Subclass: Arsenates
   Examples: Adamite, Erythrite, Legrandite, Mimetite, Olivinenite, Scorodite.

   Subclass: Vanadites
   Examples: Carnotite, Vanadinite.
 
Silicates Class: (the largest class) Nesosilicates, Sorosilicates, Inosilicates, Cyclosilicates, Phyllosilicates, Tectosilicates

The silicates are the largest, most interesting and most complicated class of minerals by far. Approximately 30% of all minerals are silicates and some geologists estimate that 90% of the Earth's crust is made up of silicates.

   Subclass: Nesosilicates (single tetrahedrons)
   Examples: Andalusite, Datolite, Euclase, Fayalite, Garnet Group, Jadeite (Pyroxene Group),
   Kyanite, Olivine (Peridot), Phenakite, Sillimanite, Sphene, Staurolite, Topaz, Willemite, Zircon.

   Subclass: Sorosilicates (double tetrahedrons)
   Examples: Danburite, Epidote group (Allanite, Epidote, Clinozoisite, Tanzanite, Zoisite),
   Hemimorphite, Idocrase (Vesuvianite).

   Subclass: Inosilicates (single and double chains)
   Examples: Amphibole Group (Actinolite, Edenite, Tremolite), Pyroxene Group (Aegirine, Augite,
   Diopside, Enstatite, Hypersthene, Jadeite, Spodumene), Neptunite, Rhodonite, Serandite.

   Subclass: Cyclosilicates (rings)
   Examples: Axinite, Benitoite, Beryl, Iolite (Cordierite, Dichroite), Dioptase, Eudyalite,
   Milarite, Tourmaline Group, Sugilite.

   Subclass: Phyllosilicates
   Examples: Apophyllite, Cavansite, Chrysocolla, Chlorite Group (Chlorite, Clinochlor,
   Kaemmererite), Lepidolite, Prehnite, Pyrophyllite, Serpentite.

   Subclass: Tektosilicates (frameworks)
   Examples: Danburite, Feldspar Group (Amazonite, Andesine, Anorthite, Bytownite,
   Labradorite, Microline, Oligoclase, Orthoclase, Plagioclase, Sanadine), Feldspathoid Group
   (Cancrinite, Leucite), Petalite, Linarite, Quartz, Scapolite, Sodalite Group (Hauyne, Lazurite,
   Sodalite), Zeolite Group (Chabazite, Natrolite, Pollucite, Scolecite, Stilbite, Thomsonite,
   Yugawaralite).
 
The Organics Class: "Minerals" composed of organic chemicals
The Organics Class covers minerals that have an organic chemical component in their formulas. Organics Class "Minerals" do not adhere to the four rules defining a mineral as follows:

1. Minerals must have a repetitive crystalline structure.
2. Minerals must have a determinable and precise formula.
3. Minerals must be natural.
4. Minerals must be inorganic.

Examples: Amber, Jet, Mellite, Opal, Pearl, Whewellite.
 
The Mineraloids: "Minerals" that lack crystal structure
The members of this unofficial class are often mistaken for minerals and are sometimes classified as minerals, but lack the necessary crystalline structure to be truly classified as minerals. Pearl, jet and amber are also the products of organic process that further remove them from full mineral status. These materials are found naturally, some are treated as gemstones and are included in most mineral references.

Examples: Amber (fossilized tree resin), Jet (very compact coal), Lechatelierite (nearly pure silica glass), Limonite (a mixture of oxides), Mercury (a liquid at normal temperatures), Obsidian (volcanic silica glass), Opal (hydrated silica), Pearl (organically produced carbonate), Tektites & Moldavite (meteoric silica glass).