Mineralogy and Rock Cycle Lecture Review

Flashcards covering vocabulary related to mineral definition, characteristics, chemical bonding, mineral classes, physical properties, societal uses, and the rock cycle based on lecture notes.

Mineral

An inorganic, naturally occurring solid with an orderly crystalline structure and a definable chemical composition.

Inorganic

Does not contain organic molecules (C-H bonds) and is generally not a product of living organisms, although some animals biomineralize.

Naturally Occurring

Formed by natural geological processes, not synthetic or human-made.

Solid

A state of matter with a definite shape and volume.

Orderly Crystalline Structure

Atoms are arranged in a specific, repeating pattern within the mineral.

Definable Chemical Composition

Minerals can be described by chemical formulae, sometimes allowing for substitutions of similar-sized/charged elements.

Elements

Describes the unique nature of different types of atoms, defined by the number of protons.

Atom

The smallest unit of an element that retains its characteristics, composed of protons, neutrons, and electrons.

Proton

A positively charged particle found in the nucleus of an atom, giving the element its identity.

Neutron

A neutral particle found in the nucleus of an atom, influencing radioactive stability and chemical signatures.

Electron

A negatively charged particle orbiting the nucleus of an atom, controlling how the atom bonds with others.

Cation

A positively charged ion formed when an atom loses electrons.

Anion

A negatively charged ion formed when an atom gains electrons.

Polymorphs

Two minerals that have the same chemical formula but different crystal structures (e.g., diamond and graphite).

Ionic Bonds

Chemical bonds formed when atoms transfer electrons, resulting in oppositely charged ions that attract each other; these bonds are generally weaker and dissolve in water.

Covalent Bonds

Chemical bonds formed when atoms share electrons to achieve a full outer shell; these bonds are generally stronger and resistant to water.

Metallic Bonds

Chemical bonds where metallic elements pack together as cations, sharing electrons freely among themselves, giving properties like electrical and thermal conductivity.

Mineral Classes

Categories of minerals primarily defined by their dominant principal anion or anionic group.

Silicates

The most abundant mineral class in the Earth's crust (90%), characterized by the silica tetrahedron (…SiO4^4-) component, often including K, Na, Al, Fe, and/or Mg.

Silica Tetrahedron

A fundamental building block of silicate minerals, composed of a silicon atom bonded covalently to four oxygen atoms, carrying a -4 net charge.

Ferromagnesian Silicates (Mafic)

Silicate minerals rich in iron (Fe) and magnesium (Mg), typically heavier, dark-colored, or green (e.g., Olivine, Pyroxene).

Non-ferromagnesian Silicates (Felsic)

Silicate minerals rich in sodium (Na), potassium (K), and aluminum (Al), typically less dense and lighter colored (e.g., Quartz, Potassium Feldspar).

Nesosilicates (Isolated Tetrahedra)

A silicate subclass where individual silica tetrahedra are bonded ionically to cations, not directly to each other (e.g., Olivine, Garnet).

Inosilicates (Chain Silicates)

A silicate subclass where tetrahedra link into single chains (e.g., Pyroxene) or double chains (e.g., Amphibole).

Phyllosilicates (Sheet Silicates)

A silicate subclass where tetrahedra link to form infinite two-dimensional sheets, often resulting in cleavage in one direction (e.g., Micas, Talc, Clays).

Tectosilicates (Framework Silicates)

A silicate subclass where tetrahedra link to form an infinite three-dimensional framework (e.g., Quartz, Feldspars).

Carbonates

A mineral class characterized by the carbonate ion (…CO3^2-), composed of 1 carbon and 3 oxygen atoms covalently bonded in triangles; many react visibly with acid (e.g., Calcite).

Sulfates

A mineral class characterized by the sulfate ion (…SO4^2-), composed of 1 sulfur and 4 oxygen atoms covalently bonded in a tetrahedron (e.g., Gypsum).

Halides

A mineral class where cation(s) are ionically bonded with group 7 anion(s) (e.g., Halite, Fluorite).

Oxides

A mineral class where a metal is bonded with oxygen (O^2-); important metal ore minerals (e.g., Hematite, Magnetite, Corundum).

Sulfides

A mineral class where a metal is bonded with sulfur (S^2-); important metal ore minerals (e.g., Pyrite, Galena).

Native Elements

A mineral class consisting of a single uncombined element (e.g., Gold, Silver, Copper, Diamond, Graphite).

Habit (Crystal Habit)

The characteristic external shape or form in which a mineral typically grows (e.g., cubic, prismatic, acicular, massive).

Massive

A description for a mineral that exhibits no clear, distinct crystal habit.

Color

A physical property of minerals that is often unreliable for identification due to variations caused by ion substitutions or trace elements.

Streak

The color of a mineral when it is powdered, obtained by rubbing the mineral across an unglazed ceramic plate; often more reliable for identification than bulk color (e.g., red-brown for hematite).

Luster

The way light reflects or refracts off the surface of a mineral, described using terms like metallic, vitreous (glassy), pearly, dull (earthy), or greasy.

Opacity

The degree to which light passes through a mineral, categorized as opaque (no light), translucent (some light, no clear image), or transparent (light passes through clearly).

Hardness

A mineral's resistance to scratching or abrasion, measured by Mohs Scale of Hardness.

Mohs Scale of Hardness

A relative scale of mineral hardness ranging from 1 (Talc, softest) to 10 (Diamond, hardest), where a harder mineral can scratch a softer one.

Cleavage

The tendency of a mineral to break cleanly along specific, repeatable flat planes of weakness in its crystal structure, defined by the number of planes and angles between them.

Fracture

The way a mineral breaks when it does not follow specific planes of weakness, resulting in irregular, uneven, or conchoidal surfaces.

Conchoidal Fracture

A special type of fracture that produces smooth, curved surfaces resembling broken glass (e.g., Quartz).

Parting

A breakage pattern in minerals that resembles cleavage but occurs along planes of structural weakness due to external forces or twinning, rather than inherent atomic planes (e.g., Corundum).

Specific Gravity

A measure of a mineral's density relative to the density of water, indicating how heavy it is for its size (e.g., Galena has a high specific gravity).

Magnetism

A specific physical property where a mineral is attracted to a magnet (e.g., Magnetite).

Acid Reactivity

A specific physical property where a mineral fizzes or reacts when a drop of acid is applied, common in carbonate minerals (e.g., Calcite).

Striations

Fine, parallel lines or grooves on the crystal faces or cleavage surfaces of some minerals, often diagnostic (e.g., Plagioclase feldspar, Pyrite).

Fluorescence

A specific physical property where a mineral emits visible light when exposed to ultraviolet (UV) light, causing it to glow.

Critical Minerals

Minerals (or elements derived from them) deemed essential for modern technology, economic stability, and national security, often subject to supply chain vulnerabilities.

Conflict Minerals

Economically valuable minerals (e.g., tungsten, tantalum, tin, gold) sourced from unstable regions where their trade finances armed groups, human rights abuses, and corruption.

Blood Diamonds

Diamonds mined in conflict zones, particularly in certain African countries, whose profits are used to finance civil wars, warlords, and human rights abuses including child soldiers and forced labor.

Mining Issues

Societal and environmental concerns related to mineral acquisition, including worker safety, child labor, pollution, and geopolitical conflicts over resource control.

Rock

A naturally occurring, solid, non-living aggregate of matter, which can be composed of one or more minerals or non-mineral matter (e.g., coal).

Igneous Rocks

Rocks formed from the cooling and solidification of magma (molten rock) either beneath the Earth's surface (intrusive) or on the surface (extrusive/volcanic).

Sedimentary Rocks

Rocks formed at or near the Earth's surface from the lithification of fragments of pre-existing rocks, biologically produced matter, or chemical precipitates from water.

Lithification

The process by which loose sediment is transformed into cohesive sedimentary rock through compaction and cementation.

Metamorphic Rocks

Rocks formed from the alteration of pre-existing igneous, sedimentary, or other metamorphic rocks by intense heat, pressure, and/or reaction with chemically active fluids.

Rock Cycle

The continuous process by which rocks are formed, broken down, and reformed through various geological processes, including weathering, erosion, deposition, lithification, melting, and metamorphism.

Basement

Refers to the underlying crystalline rock (metamorphic and intrusive igneous) that forms the foundation beneath sedimentary cover.

Bedrock

Any solid, well-consolidated body of rock (igneous, sedimentary, or metamorphic) that underlies loose surface material.

Alluvium

Unconsolidated silt, sand, or gravel deposited by flowing river water.

Colluvium

Loose deposits of soil, rock fragmenTS, and sediments accumulated at the base of slopes or in valleys, also known as 'float'.