INDEX OF ROCKS AND MINERALS
A mineral is a naturally occurring solid chemical substance that is formed through geological processes and
that has a characteristic chemical composition, a highly ordered atomic structure, and specific physical
properties. By comparison, a rock is an aggregate of minerals and/or mineraloids and does not have a
specific chemical composition. Minerals range in composition from pure elements and simple salts to very
complex silicates with thousands of known forms.
1. Basalt – Basalt is a dark-colored, fine-grained, igneous rock composed mainly of plagioclase and pyroxene
minerals. It most commonly forms as an extrusive rock, such as a lava flow, but can also form in small
intrusive bodies, such as an igneous dike or a thin sill. It has a composition similar to gabbro. The
difference between basalt and gabbro is that basalt is a fine-grained rock while gabbro is a coarse-grained
rock
2. Bauxite – Bauxite is a rock composed mainly of aluminum oxide and aluminum hydroxide minerals. These
might include: gibbsite, boehmite and diaspore. The rock usually includes other materials such as iron
hydroxides, clay, silt and free silica. It most often occurs as a residual soil material in tropical and
subtropical areas. It is the primary source of aluminum.
3. Sandstone – Sandstone is a clastic sedimentary rock made up mainly of sand-size (1/16 to 2 millimeter
diameter) weathering debris. Environments where large amounts of sand can accumulate include beaches,
deserts, flood plains and deltas.
4. Limestone – Limestone is a sedimentary rock composed primarily of calcium carbonate (CaCO3) in the
form of the mineral calcite. It most commonly forms in clear, warm, shallow marine waters. It is usually an
organic sedimentary rock that forms from the accumulation of shell, coral, algal and fecal debris. It can also
be a chemical sedimentary rock formed by the precipitation of calcium carbonate from lake or ocean water.
5. Quartzite – Quartzite is a non-foliated metamorphic rock that is produced by the metamorphism of
sandstone. It is composed primarily of quartz.
6. Granite – Granite is a light-colored igneous rock with grains large enough to be visible with the unaided
eye. It forms from the slow crystallization of magma below Earth’s surface. Granite is composed mainly of
quartz and feldspar with minor amounts of micas, amphiboles and other minerals. This mineral
composition usually gives granite a red, pink, gray or white color with dark mineral grains visible throughout
the rock.
7. Quartz – Mineral: Quartz is a chemical compound consisting of one part silicon and two parts oxygen. It is
silicon dioxide (SiO2). It is the most abundant mineral found at Earth's surface and its unique properties
make it one of the most useful natural substances.
8. Marble – Marble is a non-foliated metamorphic rock that is produced from the metamorphism of limestone.
It is composed primarily of calcium carbonate.
9. Halite – Rock Salt is a chemical sedimentary rock that forms from the evaporation of ocean or saline lake
waters. It is also known by the mineral name "halite". It is rarely found at Earth's surface, except in areas of
very arid climate. It is often mined for use in the chemical industry or for use as a winter highway treatment.
Some halite is processed for use as a seasoning for food.
10. Calcite – Mineral: Calcite is one of the most important minerals. It is extremely common and found
throughout the world in sedimentary, metamorphic and igneous rocks. In the form of limestone and marble
it makes up a significant portion of Earth's crust and serves as one of the largest carbon repositories on our
planet. The properties of calcite make it extremely useful as: construction materials, abrasives, agricultural
soil treatments, construction aggregates, pigments, pharmaceuticals and more.
11. Talc – Mineral: Talc uses include: paint, ceramics, rubber, roofing, paper.
INDEX OF ROCKS AND MINERALS
12. Olivine – Mineral: Olivine uses include: gemstones, bricks, refractory sand.
13. Red sandstone – Sandstone appearing red due to the inclusion of iron oxides (hematite).
14. Rhyolite – Rhyolite is a light-colored, fine-grained, extrusive igneous rock that typically contains quartz and
feldspar minerals.
15. Copper – Mineral: Native copper is an element and a mineral. It is found in the oxidized zones of copper
deposits; in hydrothermal veins; in the cavities of basalt that has been in contact with hydrothermal
solutions; and as pore fillings and replacements in conglomerates that have been in contact with
hydrothermal solutions. It is rarely found in large quantities, thus it is seldom the primary target of a mining
operation. Most copper produced is extracted from sulfide deposits.
16. Copper pyrite – AKA Chalcopyrite is a copper iron sulfide. It is the most commonly encountered copper
mineral and is the most important ore of copper. Chalcopyrite deposits are found in hydrothermal veins,
void fillings and replacements in limestones, contact metamorphic deposits and magmatic separations.
Minor amounts are found throughout many igneous, metamorphic and sedimentary rocks.
17. Sulfur – Mineral: Sulfur uses include: sulfuric acid, fertilizers, and sulfur compounds.
18. Muscovite mica – Mineral: Muscovite is a common rock-forming mineral. It is a mica found in many types of
igneous and metamorphic rocks. It is also found in some sediments that have not been significantly
weathered and the sedimentary rocks derived from them. It is easily recognized because of its perfect
cleavage that allows it to separate into thin, transparent, flexible sheets.
19. Hematite – Mineral: Hematite uses include: ore of iron, pigment.
20. Biotite mica – Mineral: Biotite or black mica, K(Mg,Fe2+)3(Al,Fe3+)Si3O10(OH,F)2, is rich in iron and
magnesium and typically occurs in mafic rocks.
21. Granite – #6
22. Galena – Mineral: Galena is lead sulfide, PbS, and is the most important ore of lead. Galena forms in lowand medium-temperature ore veins, along with other sulfide minerals, carbonate minerals, and quartz.
These can be found in igneous or sedimentary rocks. It often contains silver as an impurity, and silver is an
important byproduct of the lead industry.
23. Iron pyrite – Mineral: Pyrite, iron sulfide (FeS2), is a common mineral in many rocks. Pyrite is the most
important sulfur-containing mineral. (Fool’s Gold)
24. Sphalerite – Mineral: Sphalerite (SFAL-erite) is zinc sulfide (ZnS) and the foremost ore of zinc. Sphalerite
can be found in many ore veins of sulfide minerals, commonly associated with galena and pyrite. Miners
call sphalerite "jack," "blackjack," or "zinc blende." Its impurities of gallium, indium and cadmium make
sphalerite a major ore of those metals.
25. Garnet – Mineral: Garnet is a mineral family with a few green species, but most garnets range from
salmon-orange to dark ruby red. Garnet's chemical structure consists of isolated silica groups (SiO 4) that
have various metal atoms arranged around them. The six main garnet minerals belong in two groups: the
aluminum-silicate garnets are the pyralspite group (from pyrope, almandine and spessartine) and the
calcium-silicate garnets are the ugrandite group (from uvarovite, grossular and andradite).
26. Obsidian – Obsidian is an igneous rock that forms when molten rock material cools so rapidly that atoms
are unable to arrange themselves into a crystalline structure. The result is a volcanic glass with a smooth
uniform texture that breaks with a conchoidal fracture.