minerals Flashcards
what are minerals
The “building blocks” of rocks
some mineral characteristics
- Crystalline
- Orderly internal structure -> atoms arranged in a definite pattern
- Definite chemical composition
2 types of minerals
- ore minerals - extracted to obtain metals e.g. iron, copper
- Non-metals e.g. Gypsum, clay, diamond, gems.
whats an atom
smallest particle of an element that retains chemical properties
whats a nucleus
core of atom - positively charged, surrounded by a cloud of electrons
3 subatomic particles
Neutrons—electrically neutral
Protons—positively-charged
Electrons—negatively charged
*Mass of an electron «_space;mass of a proton or a neutron
whats an ion and its 2 types
atom with unequal number of electrons and protons –> a net electrical charge
= Anion—ion with negative charge e.g., O2-
= Cation—ion with positive charge e.g., Ca2+
whats a molecule
two or more atoms bonded together e.g. NaCl
what are mineral properties
The type and strength of bonding
5 type of bonds
= Covalent
= Ionic
= Metallic
= Van der Waals (primary)
= Hydrogen (primary)
whats a covalent bond
sharing of electrons – strong – hardest minerals
whats an ionic bons
bond between a metal (i.e., positively charged) and a nonmetal (i.e., negatively charged) ion through electrostatic attraction
= NaCl –> halite (table salt)
whats a metallic bond
sharing of free electrons among a lattice of metal atoms -> Atoms in “sea” of electrons => high conductivity
whats a Van der Waals bond
a secondary interatomic bond between adjacent molecular dipoles – weak
whats a hydrogen bond
the attractive interaction of a hydrogen atom with an electronegative atom that comes from another molecule
what are polymorphs
Same composition but different crystal structure
< e.g.,
= Diamond – Strong covalent bonds; hardest mineral
= Graphite – Weak Van der Waals bonds; softest mineral
what to minerals’ properties depend on
= Chemical composition
= Crystal structure
7 physical properties used to determine minerals
color, streak, hardness, specific gravity, crystal habit, crystal form, cleavage
how to determine a mineral based on its hardness
- Talc, Graphite
- Gypsum
- Calcite
- Fluorite
- Apatite
- Orthoclase
- Quartz
- Topaz
- Corundum
- Diamond
**soft to hard
how to determine a mineral based on its specific gravity
- Related to density (mass per volume)
- Mineral weight over weight of equal water volume
- Specific gravity is “heft”– How heavy it feels
how to determine a mineral based on its crystal habit
- the ideal shape of crystal faces e.g. cube, prism
- Ideal growth requires ideal conditions
how to determine a mineral based on its crystal form
Minerals vary in crystal face development e.g. well-formed faces or without
how to determine a mineral based on its cleavage
A mineral that regularly breaks along a predetermined plane has cleavage - reflect areas where atomic bonds are weak
how are minerals classified
by their dominant anion
