Physical Geology - Chapter 2

Mineral

Mineral

A naturally accuring, inorganic, crystalline solid that has a specific chemical composition (pg.30)

Atom

the smallest electronically neutral assemblies of energy and matter that we know exist in the universe (pg.32)

Nucleus

The center of an atom that holds the protons and neutrons (pg.32)

Protons

Positively charged element (pg.32)

Neutrons

neutrally charged element (pg.32)

Electrons

negatively charged element (pg.32)

Atomic Number

An element is defined by the number of protons it has in its nucleus (pg.32)

Atomic Mass Number

The total number of protons and neutrons in an atom (pg.33)

Isotopes

Atoms with the same number of protons and DIFFERENT NUMBER OF NEUTRONS (pg.33)

Ion

An atom that has a surplus or deficit of electrons relative to the number of protons in its nucleus and therefore can be either positively or negatively charged (pg.33)

Cation

A positively charges ion that has fewer electrons than protons (pg.33)

Anion

A negatively charged ion that has more electron that protons. Also the most common bonding of minerals (pg.33)

Ionic bonding

When atoms with different charges are attracted to one another (pg. 33)

Convalent Bonding

Bonding in which adjacent atoms SHARE ELECTRONS (pg.34)

Polymorphs

Minerals with the same composition but different crystalline structure (pg. 34)

Metallic Bonding

Chemical bonding that results from the attraction between metal atoms and the surrounding sea of electrons (pg. 35)

Silica

A term for oxygen combined with silicon (pg. 37)

Silicates

A name for a mineral that contains silicon and usually one or more other elements. (pg.37)

Silicon- Oxygen Tetrahedron

The basic building block for a crystal. This unit consist of 4 oxygen atoms packed together around a single much smaller silicon atom. (pg.37)

Isolated Silicate Structure

Silicate minerals that are structured so that none of the oxygen atoms are shared by silica tetrahedrons. (pg.38)

Chain Silicate Structure

Silicate structure in which two of each tetrahedron's oxygen ions are shared with adjacent tetrahedrons, resulting in a chain of tetrahedrons. (pg.39)

Sheet Silicate Structure

When each tetrahedron shares 3 oxygen atoms to form a sheet. [Examples: Mica and clay] (pg.39)

Framework Silicate Structure

When all four oxygen ions are shared by adjacent tetrahedron [Examples: Quarts] (pg.40)

Ferromagnesian Minerals

Contain iron and magnesium, darker (either green or black) and heavier (pg.43)

Streak

The color of the powder formed when a mineral is crushed. (pg.43)

Luster

The quality and intensity of light that is reflected from the surface of a mineral (pg.43)

Metallic Luster

A type of luster that give an object the appearance of being metal. (pg.43)

Nonmetallic Luster

A type of luster that doesn't give the appearance of being metal. Minerals with a nonmetallic luster are usually glassy, vitreous, pearly, earthy, silky, greasy (pg.43)

Vitreous

(also called glassy) A type of luster that gives a substance the appearance of glass or porcelain. (pg.43)

Earthy Luster

A type of luster that resembles unglazed pottery. (pg.43)

Hardness

A measure of how easily a mineral can be scratched (pg.43)

Mohs' Hardness Scale

the standard scale measuring hardness of minerals using 10 minerals in their order of increasing hardness: talc = 1; diamond = 10 (pg.43)

Crystal Form

The visible expression of a minerals internal arrangement of atoms (pg.45)

Cleavage

A mineral's ability to split easily along flat (pg.47)

Fracture

The way a substance breaks where not controlled by cleavage (pg.48)

Striations

Straight parallel lines on the surface of one of the two cleavage directions