Ch 3: Matter and Minerals Flashcards
Abrasion
The grinding and scraping of a rock surface by the friction and impact of rock particles carried by water, wind, and ice.
Ambiguous properties
Properties of minerals that may vary among different samples of the same mineral, such as color.
Atom
The smallest particle that exists as an element.
Atomic number
The number of protons in the nucleus of an atom.
Atomic weight
The average of the atomic masses of isotopes for a given element.
Augite
A black, opaque silicate mineral of the pyroxene group that is a dominant component of basalt.
Biotite
A dark, iron-rich mineral and a member of the mica family with excellent cleavage.
Cementation
One way in which sedimentary rocks are lithified. As material precipitates from water that percolates through the sediment, open spaces are filled and particles are joined into a solid mass.
Chemical bond
A strong attractive force that exists between atoms in a substance. It involves the transfer or sharing of electrons that allows each atom to attain a full valence shell.
Cleavage
The tendency of a mineral to break along planes of weak bonding.
Color
A phenomenon of light by which otherwise identical objects may be differentiated.
Column
A feature found in caves that is formed when a stalactite and stalagmite join.
Compaction
A type of lithification in which the weight of overlying material compresses more deeply buried sediment. It is most important in the finegrained sedimentary rocks such as shale.
Chemical compound (or Compound)
A substance formed by the chemical combination of two or more elements in definite proportions and usually having properties different from those of its constituent elements.
Covalent bond
A chemical bond produced by the sharing of electrons.
Crust
The very thin, outermost layer of Earth.
Crystal (or Crystalline)
Any natural solid with an ordered, repetitive atomic structure.
Crystal shape
See Habit
Dark silicate (or Ferromagnesian silicate)
A silicate mineral that contains ions of iron and/or magnesium in its structure. Dark silicates are dark in color and have a higher specific gravity than nonferromagnesian silicates.
Density
A property of matter defined as mass per unit volume.
Diagnostic properties
Properties of minerals that aid in mineral identification. Taste or feel, crystal shape, and streak are examples of diagnostic properties.
Dolostone
A chemical sedimentary rock formed from dolomite, a calcium-magnesium carbonate mineral.
Economic mineral
A concentration of a mineral resource or reserve that can be profitably extracted from Earth.
Electron
A negatively charged subatomic particle that has a negligible mass and is found outside an atom’s nucleus.
Element
A substance that cannot be decomposed into simpler substances by ordinary chemical or physical means.
Evaporite
A sedimentary rock formed of material deposited from solution by evaporation of the water.
Fracture
Any break or rupture in rock along which no appreciable movement has taken place.
Glassy
A term used to describe the texture of certain igneous rocks, such as obsidian, that contain no crystals.
Granite
An abundant, coarse-grained igneous rock composed of about 10–20 percent quartz and 50 percent potassium feldspar. Granite is used as a building material.
Groundwater
Water in the zone of saturation.
Habit
Refers to the common or characteristic shape of a crystal or an aggregate of crystals.
Hardness
A mineral’s resistance to scratching and abrasion.
Hornblende
A dark green to black mineral of the amphibole group, often found in igneous rocks.
Igneous rock
Rock formed from the crystallization of magma.
Ion
An atom or a molecule that possesses an electrical charge.
Ionic bond
A chemical bond between two oppositely charged ions that is formed by the transfer of valence electrons from one atom to the other.
Law
A formal statement of the regular manner in which a natural phenomenon occurs under given conditions.
Law of Constancy of Interfacial Angles
A law which states that the angle between equivalent faces of the same mineral is always the same.
Light silicate (or Nonferromagnesian silicate)
A silicate mineral that lacks iron and/ or magnesium. Light silicates are generally lighter in color and have lower specific gravities than dark silicates.
Limestone
A chemical sedimentary rock composed chiefly of calcite. Limestone can form by inorganic means or from biochemical processes.
Luster
The appearance or quality of light reflected from the surface of a mineral.
Metallic bond
A chemical bond that is present in all metals that may be characterized as an extreme type of electron sharing in which the electrons move freely from atom to atom.
Mineral
A naturally occurring, inorganic crystalline material with a unique chemical structure.
Mineralogy
The study of minerals.
Mohs scale
A series of 10 minerals used as a standard in determining hardness.
Muscovite
A common member of the mica family of minerals, with excellent cleavage.
Neutron
A subatomic particle found in the nucleus of an atom. The neutron is electrically neutral, with a mass approximately equal to that of a proton.
Nonferromagnesian silicate
See Light silicate
Nonsilicates
Mineral groups that lack silicas in their structures and account for less than 10 percent of Earth’s crust.
Nucleus
The small, heavy core of an atom that contains all of its positive charge and most of its mass.
Obsidian
A volcanic glass of felsic composition.
Octet rule
A rule which states that atoms combine in order that each may have the electron arrangement of a noble gas (that is, the outer energy level contains eight neutrons).
Olivine
A high temperature, dark silicate mineral typically found in basalt.
Oxidation
The removal of one or more electrons from an atom or ion. So named because elements commonly combine with oxygen.
Periodic table
An arrangement of the elements in which atomic number increases from the left to right and elements with similar properties appear in columns called families or groups.
Phase change
In geology, the process by which the atomic structure of a mineral changes although its composition remains the same.
Plagioclase feldspar
A relatively hard light silicate mineral containing both sodium and calcium ions that freely substitute for one another depending on the crystallization environment.
Polymerization
The ability of silicate tetrahedra to link to one another in a variety of configurations, including chains, sheets, and three-dimensional structures.
Polymorphs
Two or more minerals having the same chemical composition but different crystalline structures. Exemplified by the diamond and graphite forms of carbon.
Potassium feldspar
An abundant, relatively hard light silicate mineral containing potassium ions in its structure.
Principal shell
The shell or energy level an electron occupies.
Proton
A positively charged subatomic particle found in the nucleus of an atom.
Quartz
A common silicate mineral consisting entirely of silicon and oxygen that resists weathering.
Radiocarbon (carbon-14) dating
Dating of events from the very recent geologic past (the past few tens of thousands of years) based on the fact that the radioactive isotope of carbon is produced continuously in the atmosphere.
Refraction
See Wave refraction
Rock
A consolidated mixture of minerals
Rock-forming minerals
The relatively few minerals that make up most of the rocks in Earth’s crust.
Salt flat
A white crust on the ground that is produced when water evaporates and leaves behind its dissolved materials.
Sedimentary rock
Rock formed from the weathered products of preexisting rocks that have been transported, deposited, and lithified.
Sheeting
A mechanical weathering process that is characterized by the splitting off of slablike sheets of rock.
Silicate mineral
Any one of numerous minerals that have the silicon-oxygen tetrahedron as their basic structure.
Silicon-oxygen tetrahedron
A structure composed of four oxygen atoms surrounding a silicon atom that constitutes the basic building block of silicate minerals.
Slide
A movement common to mass-wasting processes in which the material moving downslope remains fairly coherent and moves along a well-defined surface.
Soil
A combination of mineral and organic matter, water, and air; the portion of the regolith that supports plant growth.
Specific gravity
The ratio of a substance’s weight to the weight of an equal volume of water.
Steno’s Law
See Law of Constancy of Interfacial Angles.
Streak
The color of a mineral in powdered form.
Striations (glacial)
Scratches or grooves in a bedrock surface caused by the grinding action of a glacier and its load of sediment.
Subduction
The process by which oceanic lithosphere plunges into the mantle along a convergent zone.
Tenacity
Describes a mineral’s toughness or resistance to breaking or deforming.
Unit cell
The smallest group of atoms, ions, or molecules that form the building block of a crystal.
Valence electron
The electrons involved in the bonding process; the electrons occupying the highest principal energy level of an atom.
