3. 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.

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

5. Quartz, Corundum, Garnet
CRYSTAL FORM
Quartz, Corundum, Garnet
Figure 3.4

6. HARDNESS
Figure 3.9

7. HARDNESS
Figure 3.8

8. Good for metallic and opaque minerals, softer than the streakplate
Figure 3.7
Good for metallic and opaque minerals, softer than the streakplate

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

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

11. EFFERVESCENCE
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

12. SPECIFIC GRAVITY Mass / Volume (gm/cm3) Orthorhombic Carbonates
All minerals have same structure, only cation differs
Mineral Formula Cation g/cm3
Aragonite CaCO
Strontianite SrCO
Witherite BaCO
Cerrusite PbCO
Figure 3.17

13. MAGNETISM
Magnetite ~ Attracted by a magnet
Figure 3.17

14. CLEAVAGE 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
Figure 3.10

15. CLEAVAGE
Figure 3.10a

16. CLEAVAGE
Figure 3.10b

17. CLEAVAGE
Figure 3.10c

18. CLEAVAGE
Figure 3.10d

19. Figure 3.12

20. Quartz (Chert), Garnet, Olivine, Corundum, no cleavage but flat ends?
NO CLEAVAGE – FRACTURE
Quartz (Chert), Garnet, Olivine,
Pyrite, Magnetite
Figure 3.12a
Corundum, no cleavage but flat ends?

21. conchoidal fracture
Fig

22. CLEAVAGE – 1 PLANE, EXCELLENT
Figure 3.12b

23. Figure 3.13

24. Gypsum: 1 good plane, two poor planes
CLEAVAGE – 2 PLANES, GOOD
Figure 3.12c
Gypsum: 1 good plane, two poor planes

25. Figure 3.15

26. Figure 3.12d

27. Figure 3.14

28. Figure 3.14a

29. Figure 3.14b

30. CLEAVAGE – 3 PLANES, GOOD
Figure 3.12e

31. CLEAVAGE – 3 PLANES, GOOD
Figure 3.12f

32. CLEAVAGE – 4 PLANES, GOOD
Figure 3.12g

33. CLEAVAGE – 6 PLANES, GOOD
Figure 3.12h

34. PAGE 90
Figure 3.18

35. PAGE 91
Figure 3.18

36. PAGE 93
Figure 3.21a

37. MULTIPLE MINERALS: Galena, Flourite
UnFigure Pg101_1

38. ONE QUARTZ CRYSTAL, DOUBLY TERMINATED
UnFigure Pg101_1b

39. MULTIPLE CRYSTALS: Galena, Flourite
UnFigure Pg101_1c

40. 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)
Fig c

41. Look at minerals: Galena, Olivine
IGNEOUS ROCK, Granite, with quartz, potassium feldspar, plagioclase, biotite
Randomly Oriented.
Look at minerals: Galena, Olivine
UnFigure Pg101_1d

42. Minerals
Silicates
quartz (crystal form, concoidal fracture, harder than glass, various colors)
plagioclase feldspar (2 planes of cleavage, striations, elongate, transluscence, pleochroism)
potassium feldspar (2 planes cleavage, opaque, blocky, pink?)
muscovite (colorless – silver mica, 1 plane of cleavage, scratch with fingernail)
biotite (black mica, 1 plane of cleavage, scratch with fingernail)
augite (pyroxene, 2 planes of cleavage at right angles, black­dark green, blocky)
hornblende (amphibole, 2 planes of cleavage ~60° & ~120°, black, elongate)
garnet (crystal form, various colors, harder than glass, no cleavage)
olivine (color, no cleavage, glassy)
kaolinite (scratch with fingernail, white to gray, massive, "clay" feel)

43. Minerals
Oxides
magnetite (magnetic, black­gray streak, color, iron oxide)
hematite (red­brown streak, hardness, metallic and non­metallic luster, various forms, iron oxide) limonite (color, hardness, streak, iron oxide)
corundum (hardness of 9, barrel shape crystal form, parting planes not considered as cleavage)
Carbonates
calcite (calcium carbonate: CaCO3, 2 planes of cleavage, effervescence, softer than glass) dolomite (calcium, magnesium carbonate: CaMg(CO3)2, similar to calcite, with less, effervescence)

44. Minerals
Other
fluorite (4 planes of cleavage, various colors)
halite (3 planes of cleavage, taste, pink to white or clear, salt)
graphite (hardness of 1, streak on paper)
pyrite (gold color, "fools gold", no cleavage, cubic crystal form, iron sulfide)
galena (very heavy, 3 planes of cleavage at right angles often "stairstepped", lead sulfide)
gypsum /selenite (scratch with fingernail, pink to white color to clear, 1 good and 2 poor planes of cleavage)