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Minerals are divided into groups or classes based on their principle chemical makeup.
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Arsenates |
The arsenates are a fairly large class of minerals consisting of compounds of metallic elements in which the arsenate radical (AsO4) is a major constituent. Most of these minerals are soft and brittle and are often brightly colored. Examples include adamite, austinite, conichalcite, and mimetite. |
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Arsenides |
The arsenides, like sulfides, are simple compounds of one or more metallic elements or semimetals only in combination with arsenic instead of sulfur. Examples include arsenopyrite, and cobaltite. |
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Borates |
The borates are compounds of one or more metallic elements in conjunction with the borate radical (BO3). There are two types of borates; anhydrous (with out water), typically developing in igneous and metamorphic environments, and hydrous borates which usually develop in sedimentary environments. Examples include borax, colemanite, howlite and ulexite. |
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Carbonates |
A large group of minerals, the carbonates are compounds of one or more metallic elements or semimetals with the carbonate radical (CO3). Some carbonates are colorful but most are white or colorless. Examples include aragonite, aurichalcite, azurite, calcite, cerrusite, dolomite, magnesite, malachite, rhodochrosite and siderite to name just a few. |
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Chromates |
The chromates are compounds of metallic elements with the chromate radical (CrO4). This is a small class of minerals, and they are usually brightly colored. Crocoite is one of the few commonly collected species. |
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Halides |
The halides are compounds in which a halogen element (chlorine, fluorine, iodine, or bromine) is the sole anion. Examples include chlorargyrite, cryolite, fluorite, and halite. |
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Hydroxides |
The hydroxides are compounds of metallic elements with water or the hydroxyl radical (OH). Examples include bauxite, brucite, geothite, limonite, manganite and psilomelane. |
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Molybdates |
The molybdates are compounds of metallic elements with the molybdate radical (MoO4). Generally, these minerals are heavy, soft, brittle, and dark or vividly colored. Scheelite, and wulfenite are examples of molybdates. |
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Multiple Oxides |
Multiple oxides are compounds of two metallic elements with oxygen. Examples include chromite, chrysoberyl, franklinite, magnetite and spinel. |
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Native Elements |
Native elements are those elements that occur in the free, uncompounded state. There are metallic elements (gold, silver, platinum, copper, iron, lead), submetallic elements (arsenic, antimony, bismuth), and nonmetallic elements (carbon, sulfur). |
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Phosphates |
The phosphates are a fairly large class of minerals consisting of compounds of metallic elements with the phosphate radical (PO4). Most of these minerals are soft and brittle and are often brightly colored. Examples include amblygonite, apatite, autunite, lazulite, monazite, pyromorphite, turquoise, varascite, vivianite and wavellite. |
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Silicates |
The silicates are the largest and most common group of minerals all sharing the silicate (Si) atomic structure. Many silicate compounds are extremely complex in composition. Some examples include actinolite, beryl, chalcedony, chlorite, diopside, dioptase, epidote, hemimorphite, hornblende, garnet, jadeite, kyanite, lazurite, mesolite, muscovite, nepheline, opal, orthoclase, stilbite, tourmaline, quartz, topaz, wollastonite and vesuvianite among many others. |
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Simple Oxides |
The simple oxides are compounds of metallic elements with oxygen. The oxides display great variety in their color, hardness and other physical characteristics. Examples include bixbyite, corundum, cuprite, hematite, pyrolusite, zincite as well as the most common oxide mineral of all: hydrogen oxide (ice)! |
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Sulfates |
The sulfates are a large group of minerals consisting of compounds of one or more metallic elements with the sulfate radical (SO4). Most sulfates are pale in color and transparent to translucent, soft and fragilie, examples include anglesite, anhydrite, barite, brochantite, celestite and gypsum. |
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Sulfides |
A large group of minerals in which sulfur is in combination with one or more metallics. Examples include acanthite, bornite, chalcocite, chalcopyrite, cinnabar, galena, pyrite, pyrrhotite, sphalerite among many others. |
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Sulfosalts |
These rare compounds consist of one or more metallic elements, sulfur plus a semimetal (antimony, arsenic, bismuth). Examples include enargite, prousite, pyrargyrite, and tetrahedrite. |
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Tellurides |
The tellurides, like sulfides, are simple compounds of one or more metallic elements or semimetals only only in combination with tellurium instead of sulfur. Tellurides are a small group of minerals. Some examples include calaverite, and sylvanite. |
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Tungstates |
The tungstates are compounds of metallic elements with the tungstate radical (WO4). Generally, these minerals are heavy, soft, brittle, and dark or vividly colored. The wolframite series of minerals are examples of tungstates. |
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Vanadates |
A fairly small class of minerals and includes compounds of metallic elements with the vanadate radical (VO4). Vanadanite is one example. |
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Vanadium Oxysalts |
The vanadium oxysalts are a small group of minerals consisting of complex compounds of metallic elements with the vanadate radical (VO4). Possibly the most interesting of these to collectors is carnotite, an ore of uranium. |