AS Minerals Flashcards
Mineral
a naturally occurring chemical substance having a definite composition and crystalline substance.
Rock
an aggregate or mixture of one or more minerals.
Sublimation
the transition of a substance directly from the gas phase to the solid phase, or the reverse, without passing through the intermediate liquid phase.
Lustre
the surface appearance of a mineral, as it interacts with light.
Crystal
a solid with the plane faces formed when atoms are arranged in a structurally ordered pattern.
Glass
an amorphous solid with no crystalline structure.
Grain boundary
the line of contact between mineral crystals in a rock.
Cations
atoms that have lost electrons leaving them with a net positive charge.
Anions
atoms that have gained electrons leaving them with a net negative charge.
Covalent bond
formed by the sharing of a pair of electrons by two atoms.
Tetrahedron
a solid contained by four triangular plane faces.
Solid solution
describes two end member crystals with defined compositions, within which one or more types of atoms may be substituted for the original atoms in the solid state, without changing the structure and allowing varied compositions between the end members.
Bridging oxygen
an oxygen atom shared by two SiO4 tetrahedra in a crystal structure.
Polymers
consist of repeating chains of smaller molecules.
Diagenesis
includes all processes that occur in sediments at low temperature and pressure at or near the Earth’s surface.
Metamorphism
the changing of the rocks in the Earth’s crust by heat and/or pressure and/or volatile content. It is isochemical and occurs in the solid state.
Igneous rock
a rock that has crystallised from magma.
Metamorphic rock
is formed by the recrystallisation of other rocks in the solid state due to pressure, temperature of both.
Partial melting
occurs when only a portion of rock in the lower crust or upper mantle is melted.
Recrystallisation
is the solid state process that changes minerals into new crystalline metamorphic minerals.
Crystallisation
occurs during the cooling of magma or lava so that solid mineral crystals form.
Burial
occurs when sediment is covered by younger layers of sediment.
Sedimentary rock
a rock composed of fragments that have been deposited, compacted and cemented.
Clast
a fragment of broken rock produced by mechanical weathering and erosion.
Magma accumulation
is magma collecting within a magma chamber.
Intrusions
composed of igneous rock formed below the Earth’s surface, where magma is forced into pre-existing rocks.
Extrusion
the emission of magma onto the Earth’s surface where it forms a lava flow.
Foliation
is a texture in metamorphic rocks formed by the preferred alignment of flat/tabular minerals.
Deposition
the laying down of sediment that occurs when a transporting agent loses energy.
Weathering
the breakdown of rocks in situ.
Erosion
the removal of weathered material, usually by the physical action of transported fragments.
Transport
the means by which weathered material is moved from one place to another by water, wind, ice or gravity.
Uplift
the return of buried rocks to the Earth’s surface by tectonic forces.
Streak
The colour of the powder left by a mineral on a streak plate
Crystal shape
Habit
Moh’s hardness scale 1
Talc
Moh’s hardness scale 2
Gypsum
Moh’s hardness scale 3
Calcite
Moh’s hardness scale 4
Fluorite
Moh’s hardness scale 5
Apatite
Moh’s hardness scale 6
Feldspar
Moh’s hardness scale 7
Quartz
Moh’s hardness scale 8
Topaz
Moh’s hardness scale 9
Corundum
Moh’s hardness scale 10
Diamond
Common object scratches hardness 1 and 2
Fingernail
Common object scratches hardness 3 and below
2p coin
Common object scratches hardness 4 and 5 and below
Steel blade/nail
Common object sometimes scratches hardness 6
Steel blade/nail
Common objects that can be scratched by hardness 7 and above
Glass
