Minerals
notes
llm
scienc
Composition, crystal structure, class occurrence, and uses of 100 minerals.
See also: Rocks VSI
Rocks versus Minerals
- mineral (noun, science)
- A solid, naturally occurring, usually inorganic substance with a definite chemical composition and characteristic physical structure and properties (such as crystalline form).
- mineraloid (noun)
- A naturally occurring substance which differs from a true mineral in some respect, esp. in having an amorphous rather than a crystalline structure.
A mineral, in modern usage is a naturally occurring, crystalline solid with a definite (though not necessarily fixed) chemical composition and an ordered atomic structure (a lattice). “Crystalline” means the atoms are arranged in a repeating 3-D pattern (a lattice + basis). The composition is usually given as a chemical formula, but it can allow for some substitution (“solid solution” ranges). In contrast, something like volcanic glass is natural but not crystalline, so it isn’t a mineral.
- rock (noun)
- The solid mineral material forming much of the substance of the earth (or any similar planetary body), whether exposed on the surface or overlain by soil, sand, mud, etc.
Rocks are distinguished by their composition and their physical properties, and consist of aggregates of minerals (very commonly silicates or calcium carbonate) and occasionally also organic matter (as in, for example, lignite and oil shale). They vary in hardness, and include soft materials such as clays. Rocks form the substance of the earth’s crust and mantle, down to the upper surface of the metallic core. Those occurring at the earth’s surface are broadly divided into three classes according to their process of formation: igneous, metamorphic, and sedimentary.
The U.S. Geological Survey offers a helpful way to remember the difference between a mineral and a rock using a baking analogy:
- A mineral is like the ingredients: Flour, sugar, butter, and chocolate chips each have a distinct and uniform composition.
- A rock is like the finished cookie: It is a mixture of all the ingredients combined together through a process (baking). Different types of cookies can be made from the same ingredients, just as different types of rocks can be made from the same minerals.
| Feature | Mineral | Rock |
|---|---|---|
| Composition | A pure substance with a definite chemical formula. For example, the mineral quartz is always composed of silicon dioxide ((SiO_{2})). | An aggregate of one or more minerals, with a variable chemical composition. For example, the rock granite contains a mixture of quartz, feldspar, and mica. |
| Structure | Has an orderly internal atomic structure, which creates a geometric, crystalline shape. | Does not have a definitive crystalline structure throughout its mass. Its structure depends on how the mineral grains are arranged. |
| Classification | Classified by its chemical composition and unique physical properties, such as hardness, luster, and crystal form. | Classified by its formation process into three main types: igneous, sedimentary, and metamorphic. |
| Formation | Formed through natural geological processes like crystallization from magma or precipitation from water. | Formed through varied processes, including the cooling of magma (igneous), the compaction of sediment (sedimentary), or the alteration of existing rocks by heat and pressure (metamorphic). |
| Variations | While a mineral has a precise chemical formula, it can have varieties based on impurities. For example, rubies and sapphires are both varieties of the mineral corundum. | A rock can be mono-mineralic (containing one mineral, like limestone) or contain multiple minerals. Its texture can also vary widely. |
Minerals
| Mineral | Formula | Crystal system | Class | Notable localities | Uses/Notes | Discovery |
|---|---|---|---|---|---|---|
| Actinolite | Ca₂(Mg,Fe)₅Si₈O₂₂(OH)₂ | Monoclinic | Amphibole | Metamorphic rocks | Fibrous varieties (asbestos) | 19th c. |
| Albite | NaAlSi₃O₈ | Triclinic | Feldspar (plagioclase) | Norway; USA | Ceramics; Na-feldspar | 19th c. |
| Almandine (garnet) | Fe₃Al₂Si₃O₁₂ | Isometric | Garnet | Schists; gneisses | Abrasive; gemstone | Ancient |
| Alunite | KAl₃(SO₄)₂(OH)₆ | Trigonal | Sulfate | Italy; USA | Alum source (historic) | 19th c. |
| Amblygonite | LiAlPO₄F | Triclinic | Phosphate | USA; Brazil | Lithium ore (historic) | 19th c. |
| Anatase | TiO₂ | Tetragonal | Oxide | Brazil; Alps; USA | TiO₂ pigment precursor; photocatalysis | 19th c. |
| Anglesite | PbSO₄ | Orthorhombic | Sulfate | UK (Anglesey); Namibia | Secondary Pb ore | 19th c. |
| Anhydrite | CaSO₄ | Orthorhombic | Sulfate | Germany; Canada | Evaporite; cement additive | 19th c. |
| Ankerite | Ca(Fe,Mg,Mn)(CO₃)₂ | Trigonal | Carbonate | Canada; UK | Fe–Mg carbonate in sediments | 19th c. |
| Anorthite | CaAl₂Si₂O₈ | Triclinic | Feldspar (plagioclase) | Italy; lunar basalts | Ca-rich plagioclase | 19th c. |
| Antigorite | (Mg,Fe)₃Si₂O₅(OH)₄ | Monoclinic | Serpentine | Serpentinized ultramafics | Serpentine group | 19th c. |
| Apatite | Ca₅(PO₄)₃(F,Cl,OH) | Hexagonal | Phosphate | Brazil; Morocco | Phosphate fertilizer; teeth/bone mineral | 18th c. |
| Aragonite | CaCO₃ | Orthorhombic | Carbonate | Spain (Aragon); seashells | Polymorph of calcite; biomineral | 18th c. |
| Arsenopyrite | FeAsS | Monoclinic | Sulfarsenide | Germany; Portugal | Principal arsenic mineral; Au association | 19th c. |
| Augite | (Ca,Na)(Mg,Fe,Al,Ti)(Si,Al)₂O₆ | Monoclinic | Pyroxene | Basalts; gabbros | Mafic rock mineral | 19th c. |
| Azurite | Cu₃(CO₃)₂(OH)₂ | Monoclinic | Carbonate | Morocco; Arizona (USA) | Cu ore; blue pigment | Ancient |
| Barite | BaSO₄ | Orthorhombic | Sulfate | China; Morocco; USA | Drilling mud weight; Ba source | 19th c. |
| Biotite | K(Mg,Fe)₃AlSi₃O₁₀(OH)₂ | Monoclinic | Mica | Igneous/metamorphic rocks | Dark mica; K–Ar dating | 19th c. |
| Bornite | Cu₅FeS₄ | Orthorhombic | Sulfide | Butte (USA); Kazakhstan; DR Congo | Copper ore; “peacock ore” tarnish | Named 1845 (Ignaz von Born) |
| Brucite | Mg(OH)₂ | Trigonal | Hydroxide | USA; Greece | Flame retardant; Mg source | 19th c. |
| Calcite | CaCO₃ | Trigonal | Carbonate | Iceland; Mexico | Cement; lime; optical spar | Ancient |
| Carnallite | KMgCl₃·6H₂O | Orthorhombic | Halide | Germany; Russia; Canada | Potash–Mg fertilizer | 19th c. |
| Cassiterite | SnO₂ | Tetragonal | Oxide | Bolivia; DRC; China | Primary tin ore | Ancient |
| Celestine | SrSO₄ | Orthorhombic | Sulfate | Madagascar; Mexico | Sr source; blue crystals | 18th c. |
| Cerussite | PbCO₃ | Orthorhombic | Carbonate | Namibia; Australia | Pb ore (secondary) | 19th c. |
| Chalcocite | Cu₂S | Monoclinic (low) | Sulfide | Cornwall (UK); USA; Chile | Enriched copper ore | Known since 19th c. |
| Chalcopyrite | CuFeS₂ | Tetragonal | Sulfide | Worldwide; Chile; Peru | Principal copper ore | Ancient |
| Chlorargyrite | AgCl | Isometric | Halide | Broken Hill (AU); NM (USA) | Silver ore (secondary); “horn silver” | 19th c. |
| Chromite | FeCr₂O₄ | Isometric | Oxide | South Africa; Kazakhstan | Chromium ore | 19th c. |
| Cinnabar | HgS | Trigonal | Sulfide | Almadén (Spain); Idrija (Slovenia); China | Principal mercury ore; vermilion pigment | Ancient |
| Clinochlore | (Mg,Fe)₅Al(AlSi₃O₁₀)(OH)₈ | Monoclinic | Chlorite | Metamorphic rocks | Green phyllosilicate | 19th c. |
| Cobaltite | CoAsS | Isometric | Sulfoarsenide | Morocco; Canada; Sweden | Cobalt ore (historic) | 19th c. |
| Copper | Cu | Isometric | Native element | Keweenaw (USA); Chile | Electrical conductor; alloys | Ancient |
| Corundum | Al₂O₃ | Trigonal | Oxide | Myanmar; Sri Lanka | Gem (ruby, sapphire); abrasive | Ancient |
| Covellite | CuS | Hexagonal | Sulfide | Vesuvius (Italy); Montana (USA) | Secondary Cu mineral; indigo blue | Named 1832 (Beudant, honoring N. Covelli) |
| Cryolite | Na₃AlF₆ | Monoclinic | Halide | Ivigtût (Greenland) | Al smelting flux (Hall–Héroult) | 19th c. |
| Cuprite | Cu₂O | Isometric | Oxide | Namibia; USA | Minor Cu ore; red crystals | 19th c. |
| Diamond | C | Isometric | Native element | South Africa; Russia; Botswana | Gemstone; cutting/abrasive | Ancient |
| Diopside | CaMgSi₂O₆ | Monoclinic | Pyroxene | Skarns; peridotites | Refractory; gem (chrome diopside) | 19th c. |
| Dolomite | CaMg(CO₃)₂ | Trigonal | Carbonate | Italy; USA | Aggregate; Mg source | 18th c. |
| Enargite | Cu₃AsS₄ | Orthorhombic | Sulfosalt | Peru; Butte (USA); Chile | Cu ore; As-bearing | 19th c. |
| Enstatite | MgSiO₃ | Orthorhombic | Pyroxene | Meteorites; peridotites | Orthopyroxene endmember | 19th c. |
| Epsomite | MgSO₄·7H₂O | Orthorhombic | Sulfate | Epsom (UK); USA | “Epsom salt”; medicinal | 17th–18th c. |
| Fluorite | CaF₂ | Isometric | Halide | Illinois (USA); England; China | Flux; HF production; optics | 18th c. |
| Galena | PbS | Isometric | Sulfide | Missouri (USA); Australia | Principal lead ore; Ag byproduct | Ancient |
| Gibbsite | Al(OH)₃ | Monoclinic | Hydroxide | Jamaica; Brazil; Australia | Bauxite component; Al ore | 19th c. |
| Goethite | FeO(OH) | Orthorhombic | Hydroxide | Worldwide (weathering product) | Iron ore (limonitic); pigment | 19th c. |
| Gold | Au | Isometric | Native element | Witwatersrand (South Africa); Nevada (USA) | Jewelry; electronics; bullion | Ancient |
| Graphite | C | Hexagonal | Native element | Sri Lanka; China | Electrodes; lubricants; pencils | Ancient |
| Gypsum | CaSO₄·2H₂O | Monoclinic | Sulfate | USA; Spain; Morocco | Plaster; drywall | Ancient |
| Halite | NaCl | Isometric | Halide | Poland; USA; China | Rock salt; chemical feedstock | Ancient |
| Hematite | Fe₂O₃ | Trigonal | Oxide | Brazil; Australia | Major iron ore; pigment | Ancient |
| Hornblende | Complex | Monoclinic | Amphibole | Metamorphic/igneous rocks | Common rock-forming amphibole | 19th c. |
| Ilmenite | FeTiO₃ | Trigonal | Oxide | Norway; Canada; Australia | Titanium feedstock | 19th c. |
| Jadeite | NaAlSi₂O₆ | Monoclinic | Pyroxene | Myanmar; Guatemala | Gem (jade) | Ancient |
| Jarosite | KFe₃(SO₄)₂(OH)₆ | Trigonal | Sulfate | Spain; acid mine sites | AMD indicator; noted on Mars | 19th c. |
| Kaolinite | Al₂Si₂O₅(OH)₄ | Triclinic | Clay mineral | Georgia (USA); China | Paper/ceramics (china clay) | Ancient |
| Leucite | KAlSi₂O₆ | Tetragonal | Feldspathoid | Italy | Alkaline lavas; fertilizer (historic) | 19th c. |
| Magnesite | MgCO₃ | Trigonal | Carbonate | Austria; Brazil | Mg source; refractories | 19th c. |
| Magnetite | Fe₃O₄ | Isometric | Oxide | Sweden; Russia; USA | Iron ore; magnetics | Ancient |
| Malachite | Cu₂CO₃(OH)₂ | Monoclinic | Carbonate | DRC; Zambia; Russia | Cu ore; gemstone; pigment | Ancient |
| Marcasite | FeS₂ | Orthorhombic | Sulfide | France; USA | Collector mineral; alters to pyrite | Ancient |
| Microcline | KAlSi₃O₈ | Triclinic | Feldspar (alkali) | Norway; USA | Ceramics; “amazonite” gem variety | 19th c. |
| Millerite | NiS | Trigonal | Sulfide | Jáchymov (CZ); Missouri (USA) | Nickel mineral; hairlike crystals | 1845 (Haidinger; after W. H. Miller) |
| Molybdenite | MoS₂ | Hexagonal | Sulfide | USA; Chile; China | Molybdenum ore; dry lubricant | 18th c. |
| Monazite | (Ce,La,Nd,Th)PO₄ | Monoclinic | Phosphate | Brazil; India; Australia | Rare-earths; Th | 19th c. |
| Muscovite | KAl₂(AlSi₃O₁₀)(OH)₂ | Monoclinic | Mica | Pegmatites; schists | Electrical insulator; sheets | 18th c. |
| Nepheline | (Na,K)AlSiO₄ | Hexagonal | Feldspathoid | Italy; Canada | Alkaline rocks; ceramics | 19th c. |
| Niccolite (Nickeline) | NiAs | Hexagonal | Arsenide | Germany; Canada | Nickel ore (minor) | 18th–19th c. |
| Olivine | (Mg,Fe)₂SiO₄ | Orthorhombic | Nesosilicate | Peridotites; basalts | Gem (peridot); mantle mineral | Ancient |
| Orpiment | As₂S₃ | Monoclinic | Sulfide | Turkey; Romania; Peru | Pigment (historic); toxic | Ancient |
| Orthoclase | KAlSi₃O₈ | Monoclinic | Feldspar (alkali) | Italy; USA | Ceramics; K-feldspar in granites | 19th c. |
| Pentlandite | (Fe,Ni)₉S₈ | Isometric | Sulfide | Sudbury (Canada); Russia | Major nickel ore | 1856 (J. F. W. Johnston; named for Pentland) |
| Phlogopite | KMg₃AlSi₃O₁₀(OH)₂ | Monoclinic | Mica | Ultramafics; marbles | Heat-resistant mica | 19th c. |
| Pyrite | FeS₂ | Isometric | Sulfide | Spain (Navajún); Peru | Sulfuric acid feed; iron ore (minor) | Ancient |
| Pyrolusite | MnO₂ | Tetragonal | Oxide | Ukraine; Gabon; South Africa | Manganese ore; depolarizer | Ancient |
| Pyrrhotite | Fe₁₋ₓS | Monoclinic–Hexagonal | Sulfide | Canada; Italy | Magnetic; Ni ore association | 19th c. |
| Quartz | SiO₂ | Trigonal | Silicate (framework) | Brazil; Arkansas (USA) | Glass; electronics; piezoelectric | Ancient |
| Realgar | AsS | Monoclinic | Sulfide | Peru; Romania; USA | Pigment (historic); photosensitive | Ancient |
| Rhodochrosite | MnCO₃ | Trigonal | Carbonate | Argentina; Colorado (USA) | Mn ore; gemstone | 19th c. |
| Rutile | TiO₂ | Tetragonal | Oxide | Brazil; USA; Norway | Ti feedstock; pigments; rutilated quartz | 19th c. |
| Siderite | FeCO₃ | Trigonal | Carbonate | Germany; UK | Iron ore (historical) | 19th c. |
| Silver | Ag | Isometric | Native element | Mexico; Peru; Canada | Jewelry; electronics; photography (historic) | Ancient |
| Smithsonite | ZnCO₃ | Trigonal | Carbonate | Namibia; Mexico | Zn ore (secondary) | 19th c. |
| Sodalite | Na₈(Al₆Si₆O₂₄)Cl₂ | Isometric | Feldspathoid | Canada; Greenland | Decorative stone; aluminosilicate | 19th c. |
| Sphalerite | ZnS | Isometric | Sulfide | Spain; USA; Mexico | Principal zinc ore | Ancient |
| Spinel | MgAl₂O₄ | Isometric | Oxide | Myanmar; Sri Lanka | Gem (spinel); refractory | Ancient |
| Stibnite | Sb₂S₃ | Orthorhombic | Sulfide | China; Japan; Romania | Antimony ore; flame retardants | Ancient |
| Strontianite | SrCO₃ | Orthorhombic | Carbonate | Strontian (Scotland); Germany | Sr source (pyrotechnics) | 18th c. |
| Sulfur | S | Orthorhombic | Native element | Sicily (Italy); USA | Sulfuric acid production; fertilizers | Ancient |
| Sylvite | KCl | Isometric | Halide | Canada; Russia; Germany | Potash fertilizer | 19th c. |
| Talc | Mg₃Si₄O₁₀(OH)₂ | Triclinic | Clay/mineral | USA; Pakistan | Softest Mohs; talcum | Ancient |
| Tennantite | (Cu,Fe)₁₂As₄S₁₃ | Isometric | Sulfosalt | Peru; Bolivia; USA | Cu ore; As-bearing analog of tetrahedrite | 19th c. |
| Tetrahedrite | (Cu,Fe)₁₂Sb₄S₁₃ | Isometric | Sulfosalt | Peru; Bolivia; USA | Cu–Ag ore; replaces tennantite | 19th c. |
| Tremolite | Ca₂Mg₅Si₈O₂₂(OH)₂ | Monoclinic | Amphibole | Dolomitic marbles | Fibrous forms (asbestos) | 19th c. |
| Turquoise | CuAl₆(PO₄)₄(OH)₈·4H₂O | Triclinic | Phosphate | Iran; USA | Gemstone | Ancient |
| Uraninite (Pitchblende) | UO₂± | Isometric | Oxide | Congo (DRC); Canada; Czechia | Uranium ore; nuclear fuel source | 19th c. |
| Vivianite | Fe₃(PO₄)₂·8H₂O | Monoclinic | Phosphate | Bog iron; fossils | Blue phosphate; Fe mineral | 19th c. |
| Wavellite | Al₃(PO₄)₂(OH,F)₃·5H₂O | Orthorhombic | Phosphate | USA; UK | Radiating aggregates; collector | 19th c. |
| Zincite | ZnO | Hexagonal | Oxide | Poland (Silesia); NJ (USA) | Zn ore (rare natural); synthetic pigment | 19th c. |
Polymorphism: the same chemical composition can crystallize in more than one structure, depending on conditions like temperature and pressure.
- Diamond vs graphite (both C) is the classic case.
- Calcite vs aragonite (both CaCO₃).
- Kyanite, andalusite, sillimanite (all Al₂SiO₅) — a famous metamorphic trio.
- Quartz, tridymite, cristobalite, coesite, stishovite (all SiO₂) — many polymorphs, each stable in different P–T ranges.
- For CuS (copper sulfide):
- Covellite (CuS) is the main recognized mineral with that exact stoichiometry.
- But copper sulfides have a rich system of related compositions and structures (chalcocite Cu₂S, djurleite Cu₁.₉₆S, anilite Cu₇S₄, etc.), and they can show nonstoichiometry (slight deviations from “ideal” Cu:S ratio).
- There aren’t really multiple named minerals of pure “CuS” with different lattices — covellite is unique for that formula.
| Crystal system | Native elements | Sulfides / sulfosalts | Halides | Oxides / hydroxides | Carbonates | Sulfates | Phosphates | Silicates |
|---|---|---|---|---|---|---|---|---|
| Isometric (cubic) | Gold (Au) Silver (Ag) Copper (Cu) Diamond (C) |
Galena (PbS) Pyrite (FeS₂) Sphalerite (ZnS) Tetrahedrite (Cu₁₂Sb₄S₁₃) |
Halite (NaCl) Sylvite (KCl) Fluorite (CaF₂) |
Magnetite (Fe₃O₄) Spinel (MgAl₂O₄) Chromite (FeCr₂O₄) |
— | — | — | Garnet group (Almandine Fe₃Al₂Si₃O₁₂ Grossular Ca₃Al₂Si₃O₁₂) |
| Tetragonal | — | Chalcopyrite (CuFeS₂) Scheelite (CaWO₄ often grouped with sulfates/tungstates) |
— | Rutile (TiO₂) Cassiterite (SnO₂) Anatase (TiO₂ polymorph) |
— | — | — | Zircon (ZrSiO₄) Vesuvianite (Ca₁₀(Mg,Fe)₂Al₄(SiO₄)₅(Si₂O₇)₂(OH,F)₄) |
| Hexagonal / trigonal | Graphite (C) Platinum (Pt) |
Covellite (CuS) Cinnabar (HgS) Millerite (NiS) |
— | Hematite (Fe₂O₃) Corundum (Al₂O₃) Ilmenite (FeTiO₃) |
Calcite (CaCO₃) Dolomite (CaMg(CO₃)₂) Rhodochrosite (MnCO₃) |
Barite (BaSO₄) Celestine (SrSO₄) Alunite (KAl₃(SO₄)₂(OH)₆) |
Apatite (Ca₅(PO₄)₃(F,Cl,OH)) Monazite ((Ce,La,Nd,Th)PO₄) |
Quartz (SiO₂) Beryl (Be₃Al₂Si₆O₁₈) Tourmaline group |
| Orthorhombic | Sulfur (S) Arsenic (As) |
Marcasite (FeS₂) Enargite (Cu₃AsS₄) Stibnite (Sb₂S₃) |
Sylvite (KCl some specimens) Carnallite (KMgCl₃·6H₂O) |
Goethite (FeO(OH)) Olivine ((Mg,Fe)₂SiO₄ as orthorhombic nesosilicate) Topaz (Al₂SiO₄(F,OH)₂) |
Aragonite (CaCO₃) Strontianite (SrCO₃) |
Anhydrite (CaSO₄) Anglesite (PbSO₄) Barite fits here too (commonly orthorhombic) |
Wavellite (Al₃(PO₄)₂(OH,F)₃·5H₂O) | Olivine ((Mg,Fe)₂SiO₄) Andalusite (Al₂SiO₅) |
| Monoclinic | — | Chalcocite (Cu₂S) Bornite (Cu₅FeS₄) Cobaltite (CoAsS) |
Carnallite (KMgCl₃·6H₂O) Cryolite (Na₃AlF₆ sometimes monoclinic) |
Cuprite (Cu₂O) Brucite (Mg(OH)₂) Chrysocolla (hydrated Cu silicate amorphous to monoclinic) |
Malachite (Cu₂CO₃(OH)₂) Azurite (Cu₃(CO₃)₂(OH)₂) Siderite (FeCO₃) |
Gypsum (CaSO₄·2H₂O) Epsomite (MgSO₄·7H₂O) Jarosite group (KFe₃(SO₄)₂(OH)₆ often monoclinic) |
Vivianite (Fe₃(PO₄)₂·8H₂O) Lazulite ((Mg,Fe)Al₂(PO₄)₂(OH)₂) |
Orthoclase (KAlSi₃O₈) Augite (CaMgSi₂O₆) Hornblende (complex amphibole) |
| Triclinic | — | — | — | — | — | — | Turquoise (CuAl₆(PO₄)₄(OH)₈·4H₂O) Amblygonite (LiAlPO₄F) |
Albite (NaAlSi₃O₈) Microcline (KAlSi₃O₈) Kaolinite (Al₂Si₂O₅(OH)₄) |
| Trigonal (often grouped with hexagonal) | — | Niccolite (NiAs) Cinnabar often trigonal |
— | Chromite (FeCr₂O₄ can also be cubic but often trigonal) |
Rhodochrosite (MnCO₃) Magnesite (MgCO₃) |
Alunite group (as above) | Monazite (REE phosphate) | Corundum often described trigonal plus kyanite/sillimanite/andalusite polymorphs |
| Group | Isometric (cubic) | Tetragonal | Hexagonal / trigonal | Orthorhombic | Monoclinic | Triclinic | Trigonal (alt.) |
|---|---|---|---|---|---|---|---|
| Native elements | Gold (Au) Silver (Ag) Copper (Cu) Diamond (C) |
— | Graphite (C) Platinum (Pt) |
Sulfur (S) Arsenic (As) |
— | — | — |
| Sulfides / sulfosalts | Galena (PbS) Pyrite (FeS₂) Sphalerite (ZnS) Tetrahedrite (Cu₁₂Sb₄S₁₃) |
Chalcopyrite (CuFeS₂) Scheelite (CaWO₄*) |
Covellite (CuS) Cinnabar (HgS) Millerite (NiS) |
Marcasite (FeS₂) Enargite (Cu₃AsS₄) Stibnite (Sb₂S₃) |
Chalcocite (Cu₂S) Bornite (Cu₅FeS₄) Cobaltite (CoAsS) |
— | Niccolite (NiAs) Cinnabar (HgS) |
| Halides | Halite (NaCl) Sylvite (KCl) Fluorite (CaF₂) |
— | — | Sylvite (KCl some) Carnallite (KMgCl₃·6H₂O) |
Carnallite (KMgCl₃·6H₂O) Cryolite (Na₃AlF₆) |
— | — |
| Oxides / hydroxides | Magnetite (Fe₃O₄) Spinel (MgAl₂O₄) Chromite (FeCr₂O₄) |
Rutile (TiO₂) Cassiterite (SnO₂) Anatase (TiO₂ polymorph) |
Hematite (Fe₂O₃) Corundum (Al₂O₃) Ilmenite (FeTiO₃) |
Goethite (FeO(OH)) Olivine ((Mg,Fe)₂SiO₄) Topaz (Al₂SiO₄(F,OH)₂) |
Cuprite (Cu₂O) Brucite (Mg(OH)₂) Chrysocolla (hydrated) |
— | Chromite (FeCr₂O₄ alt.) Corundum (trigonal description) |
| Carbonates | — | — | Calcite (CaCO₃) Dolomite (CaMg(CO₃)₂) Rhodochrosite (MnCO₃) |
Aragonite (CaCO₃) Strontianite (SrCO₃) |
Malachite (Cu₂CO₃(OH)₂) Azurite (Cu₃(CO₃)₂(OH)₂) Siderite (FeCO₃) |
— | Rhodochrosite (MnCO₃) Magnesite (MgCO₃) |
| Sulfates | — | — | Barite (BaSO₄) Celestine (SrSO₄) Alunite (KAl₃(SO₄)₂(OH)₆) |
Anhydrite (CaSO₄) Anglesite (PbSO₄) Barite (BaSO₄) |
Gypsum (CaSO₄·2H₂O) Epsomite (MgSO₄·7H₂O) Jarosite group |
— | Alunite group |
| Phosphates | — | — | Apatite (Ca₅(PO₄)₃(F,Cl,OH)) Monazite ((Ce,La,Nd,Th)PO₄) |
Wavellite (Al₃(PO₄)₂(OH,F)₃·5H₂O) | Vivianite (Fe₃(PO₄)₂·8H₂O) Lazulite ((Mg,Fe)Al₂(PO₄)₂(OH)₂) |
Turquoise (CuAl₆(PO₄)₄(OH)₈·4H₂O) Amblygonite (LiAlPO₄F) |
Monazite (alt.) |
| Silicates | Garnet group (Almandine Fe₃Al₂Si₃O₁₂ Grossular Ca₃Al₂Si₃O₁₂) |
Zircon (ZrSiO₄) Vesuvianite (Ca₁₀(Mg,Fe)₂Al₄(SiO₄)₅(Si₂O₇)₂(OH,F)₄) |
Quartz (SiO₂) Beryl (Be₃Al₂Si₆O₁₈) Tourmaline |
Olivine ((Mg,Fe)₂SiO₄) Andalusite (Al₂SiO₅) |
Orthoclase (KAlSi₃O₈) Augite (CaMgSi₂O₆) Hornblende |
Albite (NaAlSi₃O₈) Microcline (KAlSi₃O₈) Kaolinite (Al₂Si₂O₅(OH)₄) |
Corundum often grouped trigonal; sillimanite/kyanite polymorphs |
Patterns
- Isometric: simple structures, high symmetry, many ore minerals and native metals.
- Hexagonal/trigonal: home of most carbonates, many oxides, and the quartz family.
- Monoclinic/orthorhombic: catch-all for hydrated and complex anion groups (gypsum, micas, amphiboles).
- Triclinic: more complex framework silicates and phosphates (feldspars, clays, turquoise).
- Some minerals fit multiple descriptions depending on polymorph or structural nuance (e.g., corundum “trigonal” vs. “hexagonal family”).
Rocks
| Rock | Kind | Minerals | Description | Location |
|---|---|---|---|---|
| Andesite | Igneous | Plagioclase feldspar, hornblende, pyroxene | A fine-grained, grey to black volcanic rock. | Andes Mountains, Cascade Range |
| Basalt | Igneous | Pyroxene, plagioclase, olivine | A dense, dark volcanic rock, common in ocean crust. | Ocean floors, Columbia River Basalt Group |
| Diorite | Igneous | Plagioclase feldspar, hornblende, biotite | A coarse-grained intrusive rock with a speckled appearance. | Mountain-building areas, parts of the Sierra Nevada |
| Gabbro | Igneous | Pyroxene, plagioclase feldspar, olivine | A dark, coarse-grained intrusive rock. | Lower oceanic crust, Stillwater Complex in Montana |
| Granite | Igneous | Quartz, feldspar, mica | A light-coloured, coarse-grained intrusive rock. | Rocky Mountains, Scottish Highlands |
| Obsidian | Igneous | None (volcanic glass) | A naturally occurring volcanic glass formed by rapid cooling. | Yellowstone National Park |
| Pegmatite | Igneous | Quartz, feldspar, mica, and often rare minerals | A very coarse-grained intrusive igneous rock. | Associated with granite, Minas Gerais, Brazil |
| Peridotite | Igneous | Olivine, pyroxene | A dense, coarse-grained rock from the Earth’s mantle. | Earth’s mantle, kimberlite pipes in South Africa |
| Pumice | Igneous | None (volcanic glass) | A light-coloured, porous volcanic rock. | Volcanic areas like Mount Vesuvius |
| Rhyolite | Igneous | Quartz, feldspar, biotite, hornblende | A fine-grained, light-coloured volcanic rock. | Yellowstone National Park |
| Scoria | Igneous | Pyroxene, olivine, feldspar | A dark, highly vesicular volcanic rock. | Craters of the Moon National Monument in Idaho |
| Syenite | Igneous | Alkali feldspar, mica, pyroxene, amphibole | A coarse-grained rock similar to granite but lacking quartz. | Monteregian Hills in Quebec |
| Amphibolite | Metamorphic | Hornblende, plagioclase, quartz | A dark, coarse-grained rock formed under high pressure and temperature. | Mid-ocean ridges and subduction zones |
| Blueschist | Metamorphic | Glaucophane, lawsonite, jadeite | A blue-hued rock formed at high pressure and low temperature. | Subduction zones, Franciscan Complex in California |
| Eclogite | Metamorphic | Pyrope garnet, omphacite | A very dense, bright red and green rock. | Deep subduction zones |
| Gneiss | Metamorphic | Quartz, feldspar, mica, amphibole | A coarse-grained rock with distinct light and dark bands. | Lewis Range in Glacier National Park |
| Hornfels | Metamorphic | Varies, dependent on parent rock | A fine-grained, dark rock formed by contact metamorphism. | Around igneous intrusions |
| Marble | Metamorphic | Calcite or dolomite | A non-foliated rock formed from metamorphosed limestone. | Carrara, Italy, Vermont, USA |
| Phyllite | Metamorphic | Fine-grained mica, quartz, chlorite | A fine-grained rock with a silky sheen. | Appalachian Mountains |
| Quartzite | Metamorphic | Quartz | A hard, non-foliated rock formed from sandstone. | Baraboo Range in Wisconsin, Appalachians |
| Schist | Metamorphic | Mica, quartz, garnet, chlorite | A medium-grained rock with flaky, parallel mineral grains. | Manhattan Schist in New York City |
| Serpentinite | Metamorphic | Serpentine group minerals | A greenish, slippery rock often found in fault zones. | Coast Ranges in California |
| Slate | Metamorphic | Clay minerals, muscovite, quartz | A very fine-grained, dark rock that splits into thin sheets. | North Wales, Appalachian Mountains |
| Talc Schist | Metamorphic | Talc, chlorite | A soft, soapy-feeling rock. | Low-grade metamorphic environments |
| Breccia | Sedimentary | Angular fragments of various minerals and rocks | A rock composed of large, angular fragments cemented together. | Death Valley in California |
| Chalk | Sedimentary | Calcite | A soft, white, porous limestone. | White Cliffs of Dover, England |
| Chert | Sedimentary | Microcrystalline quartz | A hard, dense, microcrystalline rock. | Mississippi River Valley |
| Coal | Sedimentary | Organic carbon | A black, combustible rock formed from plant matter. | Appalachian Basin in the USA |
| Conglomerate | Sedimentary | Rounded pebbles of various rocks and minerals | A rock with rounded pebbles and granules cemented together. | Riverbeds, Titus Canyon Formation in Death Valley |
| Dolostone | Sedimentary | Dolomite | A chemical sedimentary rock similar to limestone. | Niagara Escarpment in North America |
| Gypsum | Sedimentary | Gypsum | A soft evaporite rock. | White Sands National Park in New Mexico |
| Limestone | Sedimentary | Calcite | A sedimentary rock composed mainly of calcite. | Grand Canyon, widespread in marine environments |
| Rock Salt (Halite) | Sedimentary | Halite | A chemical rock formed by the evaporation of salt water. | Salar de Uyuni in Bolivia |
| Sandstone | Sedimentary | Quartz, feldspar, rock fragments | A clastic rock made of sand-sized grains. | Utah, Arizona |
| Shale | Sedimentary | Clay minerals, quartz, silt | A fine-grained clastic rock that splits into layers. | Marcellus Shale, Appalachian Basin |
| Siltstone | Sedimentary | Quartz, feldspar, mica | A fine-grained clastic rock with a gritty feel. | Deltaic and floodplain deposits |