2. 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) 2 SiO 4 ) [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 Mineral - A naturally occurring, inorganic, homogeneous solid with a definite chemical composition and an ordered atomic arrangement.

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

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

6. Quartz SiO 2 Hardness = 7 Rose Quartz SmokeyQuartz Quartz Citrine AmethystAmethyst Carnelian Onyx Jasper

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

8. Streak : Color of powdered mineral on porcelain plate Hardness ~ 6.5 Good for metallic opaque minerals, Not good for silicates, transluscent/transparent minerals, and minerals harder than the streak plate (color of streak plate) PyriteHematite

9. Crystal Form Cleavage/Fracture Color Streak Luster Crystal Form Cleavage/Fracture Color Streak Luster Hardness Tenacity Specific Gravity Acid Test Magnetism Hardness Tenacity Specific Gravity Acid Test Magnetism Specific Gravity Specific Gravity - density of the material (g/cm 3 ) Mineral Properties

10. Specific Gravity the atomic weight of the contained elements 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 MineralFormulaCation g/cm3 AragoniteCaCO 3 202.95 StrontianiteSrCO 3 383.76 WitheriteBaCO 3 564.29 CerrusitePbCO 3 826.55

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

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

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

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

15. Hardness: resistance to scratching Compare with other objects or other mineral of known hardness. Some minerals can have a varying hardness due to impurities

16. Glass Plate (H = 5.5), very good test.

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

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

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

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

21. Minerals like calcite react with weak acid, dissolving the mineral and producing lots of bubbles (effervescence) Calcite: CaCO 3 HCl + CaCO 3 > H 2 O + Cl - + Ca + + CO 2 Dolomite: CaMg(CO 3 ) 2

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

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

24. Cleavage : Breaks along planes of weakness See the way light reflects back at you (I cannot see this for you). Rotate the mineral to “find” reflective surfaces. When you find a cleavage plane, rotate Page 82

29. conchoidalfracture Characteristic of quartz, chert and flint

30. Fig. 02.23 conchoidal fracture

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

32. One Direction of Cleavage

33. Page 83

40. Page 90

41. Page 91

42. Page 92 Alphabetical Page 90