HJD INSTITUTE OF HJD INSTITUTE OF TECHNICAL EDUCATION & TECHNICAL EDUCATION &

RESEARCHRESEARCH

PREPPERED BY: Dipesh Goswami JADEJA JAYDEEPSINH HADIYA BHAVIN

Introduction to MineralogyIntroduction to Mineralogy

Mineralogy is a mixture of:Mineralogy is a mixture of: New concepts – much of it from chemistry and New concepts – much of it from chemistry and

physics with a geologic point of viewphysics with a geologic point of view Fairly complex ideas (but not insurmountable)Fairly complex ideas (but not insurmountable) New vocabulary – many termsNew vocabulary – many terms Large amounts of memorizationLarge amounts of memorization

This mixture can make mineralogy seem a bit This mixture can make mineralogy seem a bit complicated and esotericcomplicated and esoteric

So why mineralogy?So why mineralogy? Minerals are chemical compounds that Minerals are chemical compounds that

form from natural earth processesform from natural earth processes Minerals are basic building blocks of Minerals are basic building blocks of

rocksrocks Rocks provide record of earth history and Rocks provide record of earth history and

are formed by earth processesare formed by earth processes GeologistsGeologists

Study earth historyStudy earth history Study earth processesStudy earth processes

Mineralogy is the key.Mineralogy is the key.

ObjectivesObjectives

Three parts to class (originally three Three parts to class (originally three classes):classes):

1.1. Learn chemical properties of mineralsLearn chemical properties of minerals• Crystallography – spatial arrangement of Crystallography – spatial arrangement of

atomsatoms• Crystal chemistry – what atoms make up Crystal chemistry – what atoms make up

minerals and whyminerals and why

2.2. Analytical methods:Analytical methods:• Physical properties (this week’s lab) – visual Physical properties (this week’s lab) – visual

observationsobservations• Polarizing microscopePolarizing microscope• X-ray diffractionX-ray diffraction

3.3. Identify, classify and organize mineralsIdentify, classify and organize minerals

Definition of MineralDefinition of Mineral

A A naturally occurring, naturally occurring, homogeneous solid, homogeneous solid, with a with a defined (but generally not fixed) defined (but generally not fixed) chemical composition chemical composition and an and an ordered ordered atomic arrangementatomic arrangement

Identification of minerals and Identification of minerals and their propertiestheir properties

Physical propertiesPhysical properties Chemical propertiesChemical properties Optical propertiesOptical properties X-ray analysisX-ray analysis

Physical propertiesPhysical properties Form(habit)ansForm(habit)ans ColourColour StreakStreak LustreLustre CleavageCleavage FractureFracture HardnessHardness Specific gravitySpecific gravity TransparencyTransparency TenacityTenacity FluorescenceFluorescence PhosphorescencePhosphorescence

1. Naturally occurring1. Naturally occurring Why not synthetic (man-made)?Why not synthetic (man-made)?

E.g. diamondsE.g. diamonds Corian countertops (quartz)Corian countertops (quartz) Table salt (halite)Table salt (halite) Others?Others?

San Francisco Bay

Salar de Uyuni, Bolivian Altiplano

2. Homogeneous solid2. Homogeneous solid

Minerals can not be PHYSICALLY broken Minerals can not be PHYSICALLY broken into new compoundsinto new compounds How about chemically “broken”?How about chemically “broken”? What would they break into?What would they break into?

Why solid?Why solid?

Chemical reaction: Albite Chemical reaction: Albite → Na→ Na++ + Al + Al3+3+ + SiO + SiO444-4-

Physical Reaction: Big Feldspar Physical Reaction: Big Feldspar → Little Feldspar→ Little Feldspar

3. Defined, but not fixed, 3. Defined, but not fixed, compositioncomposition

The compositions of minerals are strictly The compositions of minerals are strictly defined (stoichiometry), but can vary defined (stoichiometry), but can vary between compositionsbetween compositions

For example:For example: Calcite is CaCOCalcite is CaCO33 but will also contain much but will also contain much

Mg, Sr, Fe, Mn etc.Mg, Sr, Fe, Mn etc. Olivine - (Fe,Mg)Olivine - (Fe,Mg)22SiOSiO44 - is a group of two main - is a group of two main

minerals:minerals: Fayalite (FeFayalite (Fe22SiOSiO44)) Forsterite (MgForsterite (Mg22SiOSiO44))

4. Ordered atomic arrangement4. Ordered atomic arrangement Crystallography – how atoms are arranged Crystallography – how atoms are arranged

in space.in space. For example:For example:

Aragonite (CaCOAragonite (CaCO33) and calcite (CaCO) and calcite (CaCO33) are ) are different minerals but have identical different minerals but have identical compositionscompositions

This is why minerals are referred to by name This is why minerals are referred to by name rather than formularather than formula

Mineral names include both composition Mineral names include both composition (chemistry) and crystallography(chemistry) and crystallography

PetrologyPetrology

definition : petro means rocks definition : petro means rocks Logos means studyLogos means study Petrology deals with study of rocks.Petrology deals with study of rocks. Petrography: It is a another branch of Petrography: It is a another branch of

geology, deals with nature and distribution geology, deals with nature and distribution of rocks on the earth.of rocks on the earth.

Classification of rocksClassification of rocks

Igneous rocksIgneous rocks Sedimentary rocksSedimentary rocks Metamorphic rocksMetamorphic rocks

Igneous rocksIgneous rocks

Igneous rocks are formed by coolong and Igneous rocks are formed by coolong and solidification of magma.solidification of magma.

Examples: grenite, basalt , gabbro, Examples: grenite, basalt , gabbro, syenite, diorite, etc.syenite, diorite, etc.

Sedimentary rocksSedimentary rocks

Sediments are the products of weathering Sediments are the products of weathering since the secondary materials the rocks since the secondary materials the rocks format put of them are called sedimentary format put of them are called sedimentary rocks.rocks.

Examples: sandstones, limestones, Examples: sandstones, limestones, shale ,laterite etc.shale ,laterite etc.

Metamorphic rocksMetamorphic rocks

Metamorphic rocks are formed when the Metamorphic rocks are formed when the pre-existing rocks have been changed in pre-existing rocks have been changed in texture and composition by increased texture and composition by increased temp. and pressure.temp. and pressure.

Examples: lineation, foliation, gneissosity, Examples: lineation, foliation, gneissosity, slaty cleavage, etc.slaty cleavage, etc.

Thank You……!Thank You……!