1. Properties of Minerals

2. 1. Color Easy to see but is least reliable property for ID
many different minerals are same color (calcite, quartz, dolomite)
same mineral can come in many colors (quartz can be pink, white, clear, purple, yellow)

3. The Many Colors of Quartz
Amethyst
Rose Quartz
Smoky Quartz
Citrine
Rock Crystal

4. Many Different
White Minerals

5. Minerals Come in
Many Different Colors

6. 2. Luster How mineral shines in reflected light
metallic: like polished metal
non-metallic: all others
vitreous: glassy
pearly
dull

7. Luster
Dull
Metallic
Vitreous
Pearly

8. 3. Streak Color of powdered form of mineral
not always same color as mineral
found by rubbing mineral on unglazed tile
non-metallic minerals usu. have white streak

9. 4. Cleavage Mineral splits along flat surfaces
can cleave in 1,2 or 3 directions

12. Cleavage

13. 5. Fracture Mineral breaks along non-cleavage surfaces rough edges
conchoidal fracture: smoothly curved like inside of a shell

14. Fracture

15. 6. Hardness Mineral’s resistance to being scratched
Moh’s Scale of Hardness
compares minerals from softest (talc=1) to hardest (diamond=10)

16. Moh’s Scale of Hardness
1. Talc
2. Gypsum
3. Calcite
4. Fluorite 8. Topaz
5. Apatite 9. Corundum
6. Feldspar (ruby)
7. Quartz Diamond

18. Scratch Test Hardness Continued fingernail scratches mineral =2
penny scratches mineral =3
steel nail or file “ “ =4
mineral scratches glass =6

19. 7. Specific Gravity How dense the mineral is metallics usu.>5
non-metallics usu.<3

20. Specific Gravity Metallic minerals Non-metallic are high
minerals are lower

21. 8. Acid Test
Only CARBONATE minerals fizz in weak acid
calcite

22. 9. Crystals Not all minerals show crystals
when minerals do show crystals, they usu. have a characteristic shape

23. Quartz Crystals

24. 10. Special Properties Taste (rock salt) Smell (sulfur)
Fluorescence : glows in UV light
Radioactivity (uranium)
Double refraction: two images show through clear mineral (calcite)

25. Special Properties Sulphur- smelly Magnetite- magnetic Uraninite-
radioactive

26. Some Common Minerals
Cleavage
in 4
directions
Metallic
Galena

27. Feldspar
Cleavage
Pinkish

28. Graphite
Metallic
Very Soft
Lubricant

29. Magnetite

30. Limonite

31. Quartz

32. Aquamarine: Click for sample mineral lab.