Mineralogy Exam

Mineral

A naturally occurring, inorganic solid with a definite chemical composition and an ordered crystalline structure.

Anionic groups

Groups of atoms in minerals that largely determine bonding and structural framework, such as silicates and carbonates.

Solid solution

A variation in minerals where ions of similar size and charge substitute for one another.

Mineral species

A distinct mineral with a defined chemical composition and structure.

Mineral group

A collection of minerals that have similar structures or compositions.

Anionic classification

Minerals classified based on their dominant anion or anionic group.

Ionic bond

A type of bond formed by the transfer of electrons between atoms, resulting in charged ions.

Covalent bond

A bond formed by the sharing of electrons between atoms.

Metallic bond

A bond characterized by a 'sea' of delocalized electrons around metal cations.

Van der Waals bond

A weak attraction between molecules due to transient local partial charges.

Coordination number

The number of ions of opposite charge surrounding a central ion in a crystal structure.

Nucleation

The initial process where a crystal starts to form from a solution, lowering Gibbs free energy.

Polymorphism

The ability of a substance to exist in more than one form or crystal structure.

Quenchable reactions

Reactions where displacive changes are reversible while reconstructive changes are irreversible.

Isotropic

Materials that exhibit the same optical properties in all directions.

Anisotropic

Materials that exhibit varying optical properties in different directions.

SiO₄ tetrahedra

The fundamental building block of silicate minerals, linking to form various silicate structures.

Goldschmidt's Rules

A set of rules that governs ionic substitution in minerals based on ionic radii, charge, and electronegativity.

Hermann–Mauguin notation

A system used to describe the symmetry of crystals.

Miller Index

A notation system in crystallography that denotes the orientation of lattice planes.

Refraction

The bending of light as it passes through different materials.

Refractive index

A measure of how much light is slowed down in a material compared to a vacuum.

Mineral

A naturally occurring, inorganic solid with a definite chemical composition and an ordered crystalline structure.

Anionic groups

Groups of atoms in minerals that largely determine bonding and structural framework, such as silicates and carbonates.

Solid solution

A variation in minerals where ions of similar size and charge substitute for one another.

Mineral species

A distinct mineral with a defined chemical composition and structure.

Mineral group

A collection of minerals that have similar structures or compositions.

Anionic classification

Minerals classified based on their dominant anion or anionic group.

Ionic bond

A type of bond formed by the transfer of electrons between atoms, resulting in charged ions.

Covalent bond

A bond formed by the sharing of electrons between atoms.

Metallic bond

A bond characterized by a 'sea' of delocalized electrons around metal cations.

Van der Waals bond

A weak attraction between molecules due to transient local partial charges.

Coordination number

The number of ions of opposite charge surrounding a central ion in a crystal structure.

Nucleation

The initial process where a crystal starts to form from a solution, lowering Gibbs free energy.

Polymorphism

The ability of a substance to exist in more than one form or crystal structure.

Quenchable reactions

Reactions where displacive changes are reversible while reconstructive changes are irreversible.

Isotropic

Materials that exhibit the same optical properties in all directions.

Anisotropic

Materials that exhibit varying optical properties in different directions.

SiO

₄ tetrahedra

The fundamental building block of silicate minerals, linking to form various silicate structures.

Goldschmidt's Rules

A set of rules that governs ionic substitution in minerals based on ionic radii, charge, and electronegativity.

Hermann–Mauguin notation

A system used to describe the symmetry of crystals.

Miller Index

A notation system in crystallography that denotes the orientation of lattice planes.

Refraction

The bending of light as it passes through different materials.

Refractive index

A measure of how much light is slowed down in a material compared to a vacuum.

Unit Cell

The smallest repeating unit in a crystal lattice that displays all symmetry elements of the crystal system.

Crystal Systems

Classification of crystals into seven categories based on the symmetry of their unit cells (e.g., cubic, tetragonal, hexagonal).

Mohs Hardness Scale

A qualitative scale from 1 to 10 that characterizes the scratch resistance of various minerals.

Mineral Cleavage

The tendency of a mineral to break along specific planes of weakness, producing smooth, flat surfaces.

Birefringence

The optical property of a material, often anisotropic, where light passing through it experiences different refractive indices depending on polarization and propagation direction, leading to double refraction.

Mineral

A naturally occurring, inorganic solid with a definite chemical composition and an ordered crystalline structure.

Anionic groups

Groups of atoms in minerals that largely determine bonding and structural framework, such as silicates and carbonates.

Solid solution

A variation in minerals where ions of similar size and charge substitute for one another.

Mineral species

A distinct mineral with a defined chemical composition and structure.

Mineral group

A collection of minerals that have similar structures or compositions.

Anionic classification

Minerals classified based on their dominant anion or anionic group.

Ionic bond

A type of bond formed by the transfer of electrons between atoms, resulting in charged ions.

Covalent bond

A bond formed by the sharing of electrons between atoms.

Metallic bond

A bond characterized by a 'sea' of delocalized electrons around metal cations.

Van der Waals bond

A weak attraction between molecules due to transient local partial charges.

Coordination number

The number of ions of opposite charge surrounding a central ion in a crystal structure.

Nucleation

The initial process where a crystal starts to form from a solution, lowering Gibbs free energy.

Polymorphism

The ability of a substance to exist in more than one form or crystal structure.

Quenchable reactions

Reactions where displacive changes are reversible while reconstructive changes are irreversible.

Isotropic

Materials that exhibit the same optical properties in all directions.

Anisotropic

Materials that exhibit varying optical properties in different directions.

SiO

₄ tetrahedra

The fundamental building block of silicate minerals, linking to form various silicate structures.

Goldschmidt's Rules

A set of rules that governs ionic substitution in minerals based on ionic radii, charge, and electronegativity.

Hermann–Mauguin notation

A system used to describe the symmetry of crystals.

Miller Index

A notation system in crystallography that denotes the orientation of lattice planes.

Refraction

The bending of light as it passes through different materials.

Refractive index

A measure of how much light is slowed down in a material compared to a vacuum.

Unit Cell

The smallest repeating unit in a crystal lattice that displays all symmetry elements of the crystal system.

Crystal Systems

Classification of crystals into seven categories based on the symmetry of their unit cells (e.g., cubic, tetragonal, hexagonal).

Mohs Hardness Scale

A qualitative scale from 1 to 10 that characterizes the scratch resistance of various minerals.

Mineral Cleavage

The tendency of a mineral to break along specific planes of weakness, producing smooth, flat surfaces.

Birefringence

The optical property of a material, often anisotropic, where light passing through it experiences different refractive indices depending on polarization and propagation direction, leading to double refraction.

Crystal Habit

The characteristic external shape of a crystal or aggregate of crystals, reflecting its internal arrangement of atoms.

Mineral Fracture

The way a mineral breaks when it does not cleave along a flat plane, often resulting in irregular, conchoidal, or fibrous surfaces.

Luster

The way light interacts with the surface of a mineral, described as metallic, vitreous (glassy), dull, pearly, silky, or greasy.

Streak

The color of a mineral's powder, obtained by rubbing the mineral across an unglazed porcelain plate.

Specific Gravity

A ratio indicating how many times heavier a mineral is than an equal volume of water, used as a measure of density.

Crystal Twinning

The intergrowth of two or more crystals of the same mineral in a definite, symmetrical crystallographic orientation.

Silicate Structure Types

Categories of silicate minerals based on how SiO_4 tetrahedra link, including isolated (nesosilicates), single chains (inosilicates), double chains, sheets (phyllosilicates), and frameworks (tectosilicates).