GEOL 1110 Lecture Notes - Lecture 5: Ionic Bonding, Augite, Mafic
3 Jul 2018
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Chapter 2: Minerals
Minerals
Minerals are used daily and provide the essential materials for many daily
activities and products
Minerals have a variety of uses and value
Minerals are the “building blocks of rocks”
Minerology is the study of minerals
Geologists define minerals as any naturally occurring inorganic solids that
possess an orderly internal structure and a definite composition
A mineral must:
o1. Occur NATURALLY
o2. Be SOLID at surface and pressures
o3.It must possess an ORDERLY INTERNAL STRUCTURE (crystalline)
that s, its atoms must be arranged in a definite pattern
o4. It must have a DEFINABLE CHEMICAL COMPOSITION that can vary
within specified limits
o5. It is usually INORGANIC (although mineral formation can, in some
cases, be mediated by biologic processes)
Minerals vs. Rocks
Minerals must meet the five criteria
Rocks are solid mass of mineral or mineral like matter that occurs naturally
oSome rocks are composed f one mineral – Limestone
oSome aggregate of minerals (composed of different minerals that retain
their physical and chemical structure)
Non-mineral rock like obsidian, pumice, (non-crystalline) and coal
(organic)
Elements
4660+ minerals on Earth
oEach has a defined internal structure or chemical composition
Basic building blocks of minerals= elements
o118 elements
o92 naturally occurring
Most minerals are a combo of 2 or more elements (stable)
oGold and sulfur contain one element
Elements and Atoms
Most minerals are formed of 2 or more elements and are chemically stable and
electrically neutral
Elements are composed of atoms
Atoms are the smallest part of matter and cannot be chemically split
oComposed of a nucleus
Protons (+charge) and neutrons (no charge)
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Protons and neutrons have equal size and density
oOrbiting the nucleus are electrons
Tiny (- charge) particles ordered in shells
Shells are concentric, spherical shaped and contain different
energy levels
Atoms and their Characteristics
In elements, if the number of protons is equal to the number of electrons =
electrically neutral
Atomic number= corresponds to the number of protons in the nucleus – unique
for each element
Atomic weight = the total mass of the protons, neutrons and electrons (electron
mass is very small)
Stability= determined by the number of electrons in the outermost shell
oThe innermost shell (beside the nucleus) can hold 2 electrons, all other
shells eight
oThus stability is found when the outermost shell is full of electrons
oLess than 2 or eight can bond with other elements, thus sharing electrons
through bonds and creating a stable molecule = these outermost sharing
electrons = Valence Electrons
Bonds
Elements bond together forming complex substances (minerals or example)
oThe attractive force combining elements is called a Chemical Bond
oIf the bond unites two or more atoms in definite proportions= compound
Minerals are chemical composition
Ionic bonds
oBonds formed through transferring of electrons
oAn atom that loses or gains an electron= ion
oIons are either
Cations= (positive charge – loses electron)
Anion (Negative charge – gains electron)
The attractions between the anion and cation creates the bond- similar to the
attraction between the negative and positive charged portions of a magnet
Covalent Bonds
oAtoms that share electrons form covalent bonds (share valence electrons)
oCovalent bonds create minerals
oCovalent bonds create molecules
oVery strong bonds
Mineral Structure
A mineral is composed of an ordered array of atoms chemically bonded to form a
particularly crystalline structure
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Minerals are used daily and provide the essential materials for many daily activities and products. Minerals have a variety of uses and value. Minerals are the building blocks of rocks . Geologists define minerals as any naturally occurring inorganic solids that possess an orderly internal structure and a definite composition. Be solid at surface and pressures: 3. it must possess an orderly internal structure (crystalline) that s, its atoms must be arranged in a definite pattern, 4. It must have a definable chemical composition that can vary within specified limits: 5. It is usually inorganic (although mineral formation can, in some cases, be mediated by biologic processes) Rocks are solid mass of mineral or mineral like matter that occurs naturally: some rocks are composed f one mineral limestone, some aggregate of minerals (composed of different minerals that retain their physical and chemical structure) Non-mineral rock like obsidian, pumice, (non-crystalline) and coal (organic)
