Dynamic Interior L2 Flashcards
What is a mineral?
A naturally occurring crystalline inorganic material with a definite, but not necessarily fixed chemical composition
Where does diamond rank on the Mohs Hardness Scale?
10
Where does quartz rank on the Mohs Hardness Scale?
7
Where does a steel nail rank on the Mohs Hardness Scale?
6.5
Where does a fingernail rank on the Mohs Hardness Scale?
2.5
Where does talc rank on the Mohs Hardness Scale?
1
What are the 7 crystal systems?
Cubic
Tetragonal
Hexagonal
Trigonal
Orthorhombic
Monoclinic
Triclinic
What is a unit cell?
The smallest unit which, when repeated in 3-D, will build the crystal structure.
What are the corners of a unit cell called?
Nodes
What is a space lattice?
A 3D array of corner points (nodes)
What is the value of an atom shared between 2 units cells?
1/2
What is the value of an atom shared between 8 unit cells?
1/8
What is the value of an atom shared between 4 unit cells?
1/4
What is twinning?
Where two separate crystals are intergrown and share some common points in the crystal lattice.
What is a twin plane?
The surface between the two crystals by which atoms are arranged symmetrically.
What are the 4 types of twinning?
Rotational twinning
Simple twinning
Multiple/lamellar twinning
Cyclic twinning
What is cleavage?
The tendency of minerals to split along crystallographic planes.
What is a cleavage plane?
The crystallographic plane at which a mineral breaks.
What are two types of cleavage planes?
Single
Multiple
What is an example of a type of mineral that displays a single cleavage plane?
Sheet silicates e.g. mica
What are 2 examples of minerals that display multiple cleavage planes?
Pyroxene and amphibole
What is the chemical formula of a silicate anion?
[SiO4]4-
What does the exchange of ions with similar ionic radii into a crystal lattice produce?
Isomorph / isomorphous series
