1. Practical II Handspecimens

2. Elementary chemical composition 4000 mineral species with individual mineral names (currently) 4000 mineral species with individual mineral names (currently) Within species different polytypes: Within species different polytypes: Quartz: amethyst, citrine, rosequartz, etc.;Quartz: amethyst, citrine, rosequartz, etc.; Beryl: emerald (Cr-rich); aquamarine (Fe-rich)Beryl: emerald (Cr-rich); aquamarine (Fe-rich) Common minerals contain abundant elements: O, H, Si, Al, Na, Mg, Ca, Fe, K Common minerals contain abundant elements: O, H, Si, Al, Na, Mg, Ca, Fe, K Lithophile, chalcophile, siderophile, halogenophile Lithophile, chalcophile, siderophile, halogenophile

3. Classification of minerals Genetic: Genetic: According to principal processes by which minerals are formedAccording to principal processes by which minerals are formed Not mineralogical and problematicNot mineralogical and problematic Geochemical Geochemical Based on principal chemical elementsBased on principal chemical elements Irrational: minerals that consist of many elements?Irrational: minerals that consist of many elements? Crystal chemical Crystal chemical Functional relationship between chemical compositionFunctional relationship between chemical composition AcceptableAcceptable Geochemical and crystal chemical Geochemical and crystal chemical Very usefulVery useful

4. ClassificationClass Mineral group Minerals 1 Native elements Au, As, S 2 Sulphides and sulphosalts Galena, Realgar, arsenides 3Halides Fluorite, Halite 4 Oxides and hydroxides Chromite, Bismite 5Silicates* Neso-, Soro-, Cyclo-, Ino- (Single/Double), Phyllo-, Tecto- 6BoratesBoracite 7Carbonates Calcite, Dolomite 8 Phosphates, arsenates, vanadates Apatite, Descloizite 9 Sulphates, selenates, tellurides Gypsum 10 Wolframates, Molibenates Wolframite, wulfenite 11ChromatesCrocoite 12 Nitrates, Iodates Salpetre

5. SilicatesGroup Alternate name DescriptionMinerals Nesosilicates Ortho- or island Isolated tetrahedron Olivine, garnet Sorosilicates Double-isolated tetrahedron Epidote CyclosilicatesRing Tetrahedrons linked into isolated ring Beryl, tourmaline, cordierite Inosilicates Single chain Tetrahedrons link in infinite single chain Pyroxenes Double chain Tetrahedrons link in infinite double chain Amphiboles PhyllosilicatesSheet Tetrahedrons link in infinite sheet Micas, clay minerals TectosilicatesFramework Tetrahedrons link in infinite network Quartz, feldspars, feldspathoids

6. Movie-time!! Classification of Minerals Classification of Minerals

7. Chapter 15 Mineral identification of hand specimens

8. Movie-time!! Identification of minerals Identification of minerals

9. Stage of crystallisation Euhedral Euhedral Subhedral Subhedral Anhedral Anhedral

10. Colour, streak and luster Colour: as directly observed Colour: as directly observed Streak: colour of powdered sample Streak: colour of powdered sample Luster: character of light reflected from mineral surface Luster: character of light reflected from mineral surface

11. Mechanical properties Hardness: 1-10 Hardness: 1-10 Thumbnail2Thumbnail2 Copper penny3-4Copper penny3-4 Blade of pocket knife5-6Blade of pocket knife5-6 Quartz6-7Quartz6-7 Cleavage: Cleavage: Number of cleavage planesNumber of cleavage planes Orientation relative to each otherOrientation relative to each other Development of cleavage: Perfect, strong, weakDevelopment of cleavage: Perfect, strong, weak Fracture: Fracture: Irregular break: conchoidal, stepped, splinteryIrregular break: conchoidal, stepped, splintery Tenacity: malleable, ductile, plastic, brittle, sectile, elastically or inelastically flexible Tenacity: malleable, ductile, plastic, brittle, sectile, elastically or inelastically flexible

12. Density and specific gravity Density: mass of a unit volume of material Density: mass of a unit volume of material Gravity: ratio of the weight of a body and the weight of an equal volume of water (dimensionless) Gravity: ratio of the weight of a body and the weight of an equal volume of water (dimensionless)