1. Physical Properties of Minerals
Cleavage Fracture
Color Streak Luster Hardness Heft

2. Cleavage
- mineral breaks evenly along a smooth, flat surface the cleavage plane

3. Cleavage Minerals can have 1, 2, 3, 4 or 6 cleavage directions.
Four Directions
Six Directions
Tetrahedral
Dodecahedral

4. “1” Cleavage - Basal

5. “1” Cleavage - Basal
Topaz
Muscovite Mica
Biotite Mica

6. “2 ” Cleavage
K-Spar

7. “ 3 ” Cleavage
“3 ” vs. “3”
Calcite
Rhodochrosite 3

8. “3 ” Cleavage
Halite

9. “3 ” Cleavage
Galena

10. 4 direction Cleavage
Fluorite

11. 6 direction Cleavage
Sphalerite
Sodalite

12. Uneven Fracture

13. Splintery Fracture

14. Conchoidal Fracture

15. Granular Fracture

16. Colors of Fluorite
Iridescence

17. Distinctive Mineral Colors
Turquoise
Malachite
Azurite
Rhodochrosite

18. Streak – More Reliable
Rub the corner of the mineral against a streak plate.
(Hematite - Red-Brown Streak)
Gold Mineral-Black Streak
Gray Mineral- Red Streak

19. Luster – How a Mineral Reflects Light

20. Metallic Luster

21. Submetallic Luster

22. Vitreous (“Glassy”) Luster

23. Sub-Vitreous Luster

24. Dull Luster

25. Pearly Luster

26. Silky Luster

27. Adamantine “Sparkly” Luster

28. Resinous Luster

29. Mohs’ Hardness Scale (Relative Hardness)

30. Mohs’ Hardness Scale (Relative Hardness)

31. Mohs’ Hardness Scale (Relative Hardness)

32. Relative Hardness vs. Absolute Hardness

34. Special Properties
Chatoyancy
Asterism

35. Special Properties
Striations
Fluorescence
Iridescence