Classification and Naming of Minerals
The most commonly used systematic mineral classification scheme is based on the mineral’s chemical composition and crystal structure.
This scheme reflects the properties of the mineral and, to a certain extent, reflects the conditions of its formation and the patterns of natural elemental bonding.
Table of crystal chemical classification system of minerals
| Rank | Classification Basis | Examples |
| Major Group | Elemental and Compound Types | Oxygen-Containing Salt Minerals |
| Class | Anion or Complex Anion Type | Sulphate Minerals |
| Subgroup | Strong Bond Distribution and Complex Anion Structure | Insular Sulphate Minerals |
| Group | Crystal Structure Type and Cation Properties | Pyroxene |
| Subgroup | Cation Type and Structural Symmetry | Clinic Pyroxene |
| Species | Specific Crystal Structure and Chemical Composition | Common Pyroxene |
| Subspecies | Proportion of End-Member Components in a Complete Isomorphic Series | / |
There is no unified standard for the naming and translation of minerals. They are often named based on their characteristic morphology, physical properties, chemical composition, crystal structure, etc., or based on their place of discovery, researchers, etc.
What are some common minerals? How are they identified?
The identification of common minerals is primarily based on their various mineralogical characteristics. The following 50 common minerals are used as examples to provide a brief overview of how to identify common minerals.
Natural Element Minerals
Native element minerals include simple elements composed of only one element and miscible minerals composed of two or more metallic elements.
1. Natural Gold
| Chemical Composition | Au |
| Crystal Structure | Isometric |
| Morphology | Single crystals commonly appear as cubes, octahedrons, rhombohedrons, tetrahexahedrons, and tetrahedrons. Aggregates can exhibit dendritic, scaly, dimensional, and lumpy |
| forms. Color | Golden Yellow |
| Stripe | Golden Yellow |
| Luster | Metallic |
| Transparency | Opaque |
| Cleavage | None |
| Hardness | 2.5-3 |
| Density | 19.3 |
Gold formed at depth often exhibits an octahedral crystal form, while gold formed at medium depth exhibits rhombic dodecahedrons. Gold formed at shallow depths exhibits tetrahedral, triangular trioctahedral, and dendritic forms, among others.
(Left: octahedron; Center: rhombic dodecahedron; Right: dendritic aggregate)
2. Natural Silver
| Chemical Composition | Ag |
| Crystal Structure | Isometric |
| Morphology | Common single crystal forms include cubes, octahedrons, rhombic dodecahedrons, and tetrahedrons.Aggregates are microscopic, dendritic, and fibrous. |
| Color | Silvery-white |
| Striation | Silvery-white |
| Luster | Metallic |
| Transparency | Opaque |
| Cleavage Fracture | None |
| Hardness | 2.5-3 |
| Density | 10.1-11.1 |
3. Natural Copper
Characteristics of Natural Copper
| Chemical Composition | Cu |
| Crystal Structure | Isometric |
| Morphology | Single crystals commonly occur in cubes, octahedrons, rhombohedrons, dodecahedrons, and hexahedrons. Aggregates occur in dendritic, flake, and lumpy forms. |
| Color | Copper-red |
| Luster | Metallic |
| Transparency | Transparency |
| Cleavage Fracture | None |
| Hardness | 2.5-3 |
| Density | 8.95 |
4. Mineral Graphite
Graphite has a slippery feel and easily stains hands. It is formed by high-temperature metamorphism.
Placing zinc particles moistened with copper sulfate solution on graphite will precipitate metallic copper spots, while molybdenite does not have this reaction.
Characteristics of Graphite
| Chemical Composition | C |
| Crystal Structure | Hexagonal |
| Morphology | Single crystals are commonly found in flakes and plates. Aggregates can be scaly, massive, or earthy. |
| Color | Color |
| Striation | Striation |
| Luster | Semi-metallic |
| Transparency | Opaque |
| Cleavage Fracture | Very Complete |
| Hardness | 1-2 |
| Density | 2.21-2.26 |
5. Mineral Diamond
Diamond is the hardest naturally occurring substance, rivaling only diamond. The hardness of each facet of diamond varies slightly across different crystal forms: the hardness of the octahedral face is greater than the hardness of the rhombic dodecahedral face, which is greater than the hardness of the cubic face.
Diamond Properties
| Chemical Composition | C |
| Crystal Structure | Isometric |
| Morphology | Single crystals often form octahedrons and rhombic dodecahedrons, with polycrystals of octahedrons, rhombic dodecahedrons, and hexahedrons also being observed. |
| Color | Colorless and transparent |
| Luster | Diamond luster, with an oily sheen on the fracture |
| Transparency | Transparent |
| Cleavage Fracture | Moderate cleavage |
| Hardness | 10 |
| Density | 3.52 |
Sulfide and Similar Compound Minerals
Sulfide minerals are minerals formed by the combination of metal cations and sulfur. Similar compounds of sulfide minerals include selenides, tellurides, arsenides, antimonides, and bismuths, formed by the combination of metal elements with selenium, tellurium, arsenic, antimony, and bismuth.
6. Mineral Pyrite
The striations on adjacent faces of pyrite are perpendicular to each other.
Pyrite Properties
| Chemical Composition | Fe[S-] |
| Crystal Structure | Isometric |
| Morphology | Single crystals commonly occur in cubes, octahedrons, and pentagonal dodecahedrons. Aggregates occur in granular, blocky, nodular, and strawberry shapes. |
| Color | Light copper-yellow |
| Striation | Dark green |
| Luster | Strong metallic luster |
| Transparency | Opaque |
| Cleavage Fracture | No cleavage, jagged fracture |
| Hardness | 6-6.5 |
| Density | 4.9-5.2 |
7. Mineral Chalcopyrite
Chalcopyrite is very similar to pyrite, but chalcopyrite is yellower.
Chalcopyrite Properties
| Chemical Composition | CuFeS2 |
| Crystal Structure | Tetragonal |
| Appearance | Single crystals are tetrahedral, but rare. Dense blocks and dispersed granular aggregates are common. |
| Color | Dark brass |
| Stripe | Dark green |
| Luster | Metallic |
| Transparency | Opaque |
| Cleavage | Incomplete |
| Hardness | 3-4 |
| Density | 4.1-4.3 |
8. Mineral Realgar
Realgar turns pale orange-red powder after prolonged exposure to sunlight.
Realgar Properties
| Chemical Composition | As4S4 |
| Crystal Structure | Monoclinic |
| Morphology | Single crystals in the form of columns, short columns, or needles, with longitudinal striations on the columnar surface. Commonly found in granular, earthy, or crusty aggregates. |
| Color | Orange-red |
| Striation | Light orange-red |
| Luster | Diamond-like luster on crystal surfaces, resinous luster on cross-section |
| Transparency | Transparent to translucent |
| Cleavage Fracture | Complete cleavage |
| Hardness | 1.5-2 |
| Density | 3.6 |
9. Mineral Orpiment
Orpiment Properties
| Chemical Composition | AszS3 |
| Crystal Structure | Monoclinic |
| Morphology | Single crystals are plate-like or short columnar, with curved crystal faces and longitudinal striations on the columnar surfaces. Commonly found are flake-like, comb-like, earthy, and radial aggregates. |
| Color | Lemon yellow |
| Striation | Bright yellow |
| Luster | Greasey to adamantine |
| Transparency | Transparent to translucent |
| Cleavage Fracture | Very complete |
| Hardness | 1.5-2 |
| Density | 3.5 |
10. Mineral Cinnabar
Cinnabar Properties
| Chemical Composition | HgS |
| Crystal Structure | Trigonal |
| Morphology | Single crystal rhombohedron. Commonly found in granular, filmy, or crusty aggregates. |
| Color | Bright red, lead-gray eye |
| Striation | Red |
| Luster | Diamond-like |
| Transparency | Translucent |
| Cleavage Fracture | Complete |
| Hardness | 2-2.5 |
| Density | 8-8.2 |
11. Mineral Stibnite/Antimonite
Stibnite Properties
| Chemical Composition | Sb2S3 |
| Crystal Structure | Orthorhombic |
| Morphology | Single crystals are columnar or needle-shaped, with longitudinal striations on the columnar surface and curved crystals. Commonly found in radial and clustered forms. |
| Color | Lead gray, steel gray, dark blue-eye |
| Striation | Black |
| Luster | Diamond-like |
| Transparency | Opaque |
| Cleavage Fracture | Complete |
| Hardness | 2 |
| Density | 4.6 |
12. Mineral Galena
Galena Chemical Properties
| Chemical Composition | HgS |
| Crystal Structure | Isometric |
| Morphology | Single crystal cube, octahedron. Common: Granular aggregates. |
| Color | Lead gray |
| Striation | Dark gray |
| Luster | Metallic |
| Cleavage Fracture | Complete |
| Hardness | 2-3 |
| Density | 7.4-7.6 |
13.Mineral Sphalerite
Sphalerite Chemical Properties
| Chemical Composition | ZnS |
| Crystal Structure | Isometric |
| Morphology | Single crystal tetrahedron, rhombic dodecahedron, cube, triangular tetrahedron. Commonly found as granular aggregates; less common as kidney-shaped or grape-shaped aggregates. |
| Color | Light yellow, tan, black |
| Striation | White to brown |
| Luster | Resin-like to semi-metallic |
| Transparency | Transparent to translucent |
| Cleavage Fracture | Complete |
| Hardness | 3.5-4 |
| Density | 3.9-4.2 |
Oxide Minerals
Oxide minerals are compounds formed by the combination of metal cations with O²⁻ and (OH). Over 300 species have been discovered, including over 200 oxides and over 80 hydroxides. They account for 17% of the mass of the Earth’s crust, second only to oxygen-containing salt minerals.
14. Mineral Quartz
Chemical Properties of Quartz
| Chemical Composition | SiO2 |
| Crystal Structure | Trigonal |
| Morphology | Single crystals often present as hexagonal prisms and rhombohedral aggregates, with horizontal striations on the prisms. Common aggregates include comb-shaped, granular, dense massive, and cluster-like forms. Cryptocrystalline aggregates often present as kidney-shaped, stalactite-shaped, nodular, multicolored concentric bands, and multicolored dense massive forms. |
| Color | Colorless, milky white, gray |
| Luster | Vitreous |
| Transparency | Opaque, greasy gloss on fracture |
| Cleavage Fracture | No cleavage, conchoidal fracture |
| Hardness | 7 |
| Density | 2.65 |
15. Mineral Corundum
Corundum Chemical Properties
| Chemical Composition | Al₂O₃ |
| Crystal Structure | Trigonal |
| Appearance | Single crystals are drum-shaped or columnar, rarely plate-shaped or flake-shaped. Commonly found are granular or dense massive aggregates. |
| Color | Gray, Grayish yellow |
| Luster | Vitreous |
| Transparency | Transparent |
| Cleavage Fracture | None |
| Hardness | 9 |
| Density | 3.95-4.10 |
16. Mineral Hematite
Chemical Properties of Hematite
| Chemical Composition | Fe₂O₃ |
| Crystal Structure | Trigonal |
| Appearance | Single crystal plate. Common forms include flakes (mirrorite), scales (mica hematite), or massive phaneritic aggregates, and nephriform, reniform, powdery, and earthy cryptocrystalline aggregates. |
| Color | haneritic is iron black or steel gray, while cryptocrystalline is dark red or bright red. |
| Striation | Cherry red |
| Luster | Metallic to semi-metallic, earthy. |
| Transparency | Opaque. |
| Cleavage Fracture | Complete cleavage. |
| Hardness | 5-6 |
17. Mineral Spinel
Spinel Chemical Properties
| Chemical Composition | MgAl₂O₄ |
| Crystal Structure | Isometric |
| Morphology | Single octahedral crystal. Commonly found as granular aggregates. |
| Color | Red, green, dark brown |
| Luster | Vitreous |
| Transparency | Transparent |
| Cleavage Fracture | None |
| Hardness | 7 |
| Density | 3.55 |
18. Mineral Magnetite
Chemical Properties of Magnetite
| Chemical Composition | FeFe2O4 |
| Crystal Structure | Isometric |
| Morphology | Single octahedron, rarely rhombic dodecahedron. Commonly found in dense massive and granular aggregates. |
| Color | Iron-black |
| Striation | Black |
| Luster | Semi-metallic |
| Transparency | Opaque |
| Hardness | 6 |
| Density | 5.18 |
Halide Minerals
Halide minerals are compounds formed by the combination of halogen anions and metal cations. There are over 100 species. Fluorides and chlorides are the most common, while bromides and iodides are extremely rare.
19. Mineral Fluorite
Chemical Properties of Fluorite
| Chemical Composition | CaF₂ |
| Crystal Structure | Isometric |
| Morphology | Single crystals in cubes, octahedrons, rhombuses, dodecahedrons, and sometimes tetrahexahedrons and hexahedrons. Common forms include granular, massive, and aggregates. |
| Color | Green, purple, blue, colorless, and nearly all other colors. |
| Striation | White |
| Luster | Vitreous |
| Transparency | Transparent |
| Cleavage Fracture | Complete |
| Hardness | 4 |
| Density | 3.18 |
Oxygen-containing salt minerals
Oxygen-containing salts are compounds formed by the combination of metal cations and various forms of oxygen-containing acid complex anions.
20. Mineral Calcite
Chemical Properties of Calcite
| Chemical Composition | Ca[CO₃] |
| Crystal Structure | Trigonal |
| Morphology | Single crystals vary in form, with over 600 aggregates. Common forms include granular (marble), platy (calcite), fibrous (fibrous calcite), earthy (chalk), porous (travertine), dense massive (limestone), stalactite (stalactites), spherical, bean-shaped, nodular, grape-shaped, membrane-shaped, and cluster-shaped aggregates. |
| Color | White, colorless, etc. |
| Striation | White |
| Luster | Vitreous |
| Transparency | Transparent to translucent |
| Cleavage Fracture | Complete cleavage |
21. Mineral Dolomite
Chemical Properties of Dolomite
| Chemical Composition | CaMg[CO₃]₂ |
| Crystal Structure | Trigonal |
| Morphology | Single crystal rhombohedron with curved crystal faces. Common forms include granular, massive, porous, and kidney-shaped aggregates. |
| Color | Colorless, white |
| Luster | Vitreous |
| Transparency | Transparent |
| Cleavage Fracture | Complete |
| Hardness | 3.5-4 |
| Density | 2.85 |
22. Mineral Aragonite
Chemical Properties of Aragonite
| Chemical Composition | Ca[CO₃] |
| Crystal Structure | Orthorhombic |
| Morphology | ingle crystals are commonly columnar or spear-shaped. Common forms include fibrous, columnar, stalactite, spherical, bean-shaped, spherical, coral-shaped, drusy, and crusty aggregates. |
| Color | White, yellowish-white |
| Streak | White |
| Luster | Vitreous, with an oily sheen on the fracture |
| Transparency | Transparent to translucent |
| Cleavage | Incomplete to moderate cleavage, with a shell-like fracture |
| Hardness | 3.5-4.5 |
| Density | 2.6-2.9 |
23. Mineral Rhodochrosite
Chemical Properties of Rhodochrosite
| Chemical Composition | Mn[CO₃] |
| Crystal Structure | Trigonal |
| Morphology | Single crystal rhombohedron with curved crystal faces. Commonly found in aggregates: granular, massive, earthy, and oolitic. |
| Color | Pale rose-red, purple-red |
| Striation | Off-white |
| Luster | Vitreous |
| Transparency | Transparent to translucent |
| Cleavage Fracture | Complete |
| Hardness | 3.5-4.5 |
| Density | 3.6-3.7 |
24. Malachite Mineral
Malachite Chemical Properties
| Chemical Composition | Cu₂[CO₃](OH)₂ |
| Crystal Structure | Monoclinic |
| Morphology | Single crystals are commonly columnar, acicular, or fibrous. Kidney-shaped, grape-shaped, and crusty aggregates are common; sometimes crystal clusters, vein-shaped, and earthy forms are also observed. |
| Color | Malachite Green |
| Striation | Light Green |
| Luster | Glassy-adamantine, silky |
| Transparency | Transparent |
| Cleavage Fracture | Complete |
| Hardness | 3.5-4 |
| Density | 4.0-4.5 |
25. Mineral Azurite
Chemical Properties of Azurite
| Chemical Composition | Cu₃[CO₃]₂(OH)₂ |
| Crystal Structure | Trigonal |
| Morphology | Single crystals in the form of short prisms, columns, or thick plates. Common forms include granular, cluster, earthy, and crusty aggregates. |
| Color | Light blue |
| Striation | Off-white |
| Luster | Vitreous |
| Transparency | Transparent to translucent |
| Cleavage | Moderate to complete, conchoidal |
| Hardness | 3.5-4 |
| Density: | 3.7-3.9 |
Sulfate Mineral
26. Gypsum mineral
Gypsum chemical properties
| Chemical composition | Ca[SO₄]·2H₂O |
| Crystal structure | Monoclinic |
| Morphology | Single crystals, plate-like or granular, with longitudinal grains on the surface. Commonly found in earthy, flaky, and rosette-like aggregates. |
| Color | Color |
| Striation | White |
| Luster | Vitreous, pearly on cleavage surfaces, silky |
| Transparency | Transparent |
| Cleavage fracture | Medium to complete |
| Hardness | 1.5-2 |
| Density | 2.3 |
27. Mineral Barite
Chemical Properties of Barite
| Chemical Composition | Ba[SO4] |
| Crystal Structure | Orthorhombic |
| Morphology | Single crystals in the form of plates or columns. Granular aggregates are common. |
| Color | White, gray, light yellow, light brown |
| Luster | Vitreous, pearly on cleavage surfaces |
| Transparency | Transparent to translucent |
| Cleavage Fracture | Medium to complete |
| Hardness | 3-3.5 |
| Density | 4.3-4.5 |
28. Mineral Apatite
Chemical Properties of Apatite
| Chemical Composition | Ca₅[PO₄]₃(OH, F, CI) |
| Crystal Structure | Hexagonal |
| Morphology | Single crystals in hexagonal prisms and plates. Commonly found in granular and dense massive aggregates. |
| Color | Light green, yellow-green, brown-red, light purple |
| Striation | White |
| Luster | Vitreous, with a greasy sheen on the fracture |
| Transparency | Transparent |
| Cleavage Fracture | Incomplete |
| Hardness | 5 |
| Density | 3.18-3.21 |
29. Turquoise Mineral
Turquoise Chemical Properties
| Chemical Composition | CuAl₆(PO₄)₄(OH)₄·4H2O |
| Crystal Structure | Triclinic |
| Morphology | Single crystal columnar. Commonly found in dense, blocky, and nodular cryptocrystalline aggregates. |
| Color | Sky blue, yellow-green |
| Striation | White |
| Luster | Waxy |
| Transparency | Transparent |
| Cleavage | Complete to moderate |
| Hardness | 5-6 |
| Density | 2.60-2.80 |
30. Mineral Olivine
Chemical Properties of Olivine
| Chemical Composition | (Mg, Fe)₂[SiO₄] |
| Crystal Structure | Orthorhombic |
| Morphology | Single crystals in thick plates or columns. Granular forms are common. |
| Color | Olive green, light green, dark green, etc. |
| Luster | Vitreous |
| Transparency | Transparent to translucent |
| Cleavage | Moderate cleavage, conchoidal fracture |
| Hardness | 6.5-7 |
| Density | 3.27-4.37 |