inorganic - not formed by organic chemistry (e.g., sugars, etc.)

1. Mineral- A naturally occurring, inorganic, homogeneous solid with a definite chemical composition and an ordered atomic arrangement. naturally occurring - materials synthesized in laboratory do not count, must be formed by natural processes in wild inorganic - not formed by organic chemistry (e.g., sugars, etc.) homogeneous solid - single substance in solid phase which cannot be physically separated into simpler compounds definite chemical composition - composition can be represented as chemical formula (e.g., NaCl), although variation in exact composition is possible (e.g., (Mg, Fe)2SiO4 ) [range in color, hardness, specific gravity] ordered atomic arrangement – repeating structure at the atomic level, which expresses as symmetry in large specimens, i.e., crystalline structure. http://www.uoregon.edu/~jrice/geol311

2. Crystal Form Cleavage/Fracture Color Streak Color Luster Hardness Tenacity Specific Gravity Acid Test Magnetism Mineral Properties Crystal symmetry is controlled by the atomic structure of mineral

4. Crystal Form Cleavage/Fracture Color Streak Color Luster Hardness Tenacity Specific Gravity Acid Test Magnetism Mineral Properties Characteristic for some minerals, useless for most

5. Quartz Citrine Carnelian Onyx Jasper Rose Quartz Quartz SiO2 Smokey Quartz Hardness = 7 Amethyst Amethyst

6. Crystal Form Cleavage/Fracture Color Streak Color Luster Hardness Tenacity Specific Gravity Acid Test Magnetism Mineral Properties Streak Color - Color of powdered mineral, which may or may not be the color of the crystal

7. hematite streak color

8. Crystal Form Cleavage/Fracture Color Streak Luster Hardness Tenacity Specific Gravity Acid Test Magnetism Mineral Properties Specific Gravity - density of the material (g/cm3)

9. Specific Gravity Related to both the atomic weight of the contained elements, and how tightly the atoms are packed Orthorhombic Carbonates All minerals have same structure, only cation differs Mineral Formula Cation g/cm3 Aragonite CaCO320 2.95 StrontianiteSrCO338 3.76 WitheriteBaCO356 4.29 CerrusitePbCO382 6.55 See Page 82 in Lab Manual for Specific Gravities of some minerals

10. Crystal Form Cleavage/Fracture Color Streak Color Luster Hardness Tenacity Specific Gravity Acid Test Magnetism Mineral Properties Luster - quality of light reflected from mineral surface

11. Luster - quality of light reflected from mineral surface pyrite metallic silver gold

12. Luster quality of light reflected from mineral surface non-metallic Some minerals may be listed in both metallic and non-metallic, or in the incorrect table, i.e., limonite vitreous (glassy) pearly resinous

13. Crystal Form Cleavage/Fracture Color Streak Color Luster Hardness Tenacity Specific Gravity Acid Test Magnetism Mineral Properties Hardness - resistance of mineral to scratching or abrasion

14. glass plate copper penny fingernail Mohs Hardness Scale Austrian mineralogist F. Mohs, 1824 Higher numbered minerals scratch lower numbered minerals Based on relative hardness of 10 common minerals hard 10. Diamond C 9. Corundum Al2O3 8. Topaz Al2SiO4(F,OH)2 7. Quartz SiO2 6. Orthoclase KAlSi3O8 5. Apatite Ca5(PO4)3(F,Cl,OH) 4. Fluorite CaF2 3. Calcite CaCO3 2. Gypsum CaSO4 1. Talc Mg3Si4O10(OH)2 soft

15. Muscovite Hardness < 2 Can scratch with fingernail (H=2.5) Fig. 02.14

16. Fluorite Hardness =4 Can scratch copper penny (H=3.5), but not glass plate (H=5.5) Fig. 02.15c

17. Quartz Hardness =7 Scratches glass plate (H=5.5). Hardest of common minerals Fig. 02.15a

18. Crystal Form Cleavage/Fracture Color Streak Luster Hardness Tenacity Specific Gravity Acid Test Magnetism Mineral Properties Reaction to dilute acid; especially useful in identifying carbonate minerals

19. Minerals like calcite react with weak acid, dissolving the mineral and producing lots of bubbles (effervescence) Calcite: CaCO3 HCl + CaCO3 > H2O + Cl- + Ca+ + CO2 Dolomite: CaMg(CO3)2

20. Crystal Form Cleavage/Fracture Color Streak Luster Hardness Tenacity Specific Gravity Acid Test Magnetism Mineral Properties Some minerals strongly attract magnets. Characteristic of magnetite and some other iron minerals

21. Crystal Form Cleavage/Fracture Color Streak Color Luster Hardness Tenacity Specific Gravity Acid Test Magnetism Mineral Properties Fracture -any breakage that is not cleavage

22. conchoidal fracture Characteristic of quartz, chert and flint

23. conchoidal fracture Fig. 02.23

24. Crystal Form Cleavage/Fracture Color Streak Color Luster Hardness Tenacity Specific Gravity Acid Test Magnetism Mineral Properties Cleavage -tendency to split along planes of weakness corresponding to weaker chemical links in internal structure of crystal

25. A single crystal can display several cleavage directions. 1 direction 2 directions The cleavage directions are not always at right angles to each other. They also are not necessarily parallel to the crystal faces of the mineral.

26. One Direction of Cleavage Fig. 02.19a

27. One Direction of Cleavage

28. Cleavage Direction Each set of parallel planes of weakness is one direction Two Directions of Cleavage

29. Three Directions of Cleavage

30. Fig. 02.22 http://www.geology.sdsu.edu/visualgeology

31. Four Directions of Cleavage Fluorite Crystals http://www.xpsdata.com/ http://www.greatsouth.net/ Six directions of Cleavage: Sphalerite (ZnS)