THE CASE OF THE SCARLETT STREAK:

1. THE CASE OF THE SCARLETT STREAK:MINERAL IDENTIFICATION Virginia T. McLemore New Mexico Bureau of Geology and Mineral Resources New Mexico Tech

2. What is a mineral?

3. What is a mineral? • naturally occurring • inorganic • solid • homogeneous • crystalline material • with a unique chemical element or compound with a set chemical formula • usually obtained from the ground

4. A crystal is composed of a structural unit that is repeated in three dimensions. This is the basic structural unit of a crystal of sodium chloride, the mineral halite.

5. Why are minerals important?

6. Why are minerals important? • Identification of rocks • commodities that we use every day • foundation of understanding geology and geologic processes that affect us everyday • understanding geologic hazards

8. NEW MEXICO MINING: WHERE ARE THE DEPOSITS?

9. New Mexico is at the edge of one of the world’s greatest metal-bearing provinces

10. Active mines in New Mexico 2002-2005 (excluding aggregates)

11. Active aggregate mines in New Mexico.

12. Stone House zeolite mine, Sierra County (18.3 million tons of reserves).

13. Metals districts with Significant depositsin New Mexico

14. Minerals have distinctive physical and chemical properties that allow for their identification.

15. Habit (Crystal forms and shapes) Hardness Cleavage Streak Color Luster Transparency Twinning Fracture Specific Gravity Associated Minerals Fluorescence Magnetism Odor Feel Taste Solubility Reaction to acids Radioactive minerals Meteoritic minerals Properties of minerals

16. Hardness

17. Hardness • ease or difficulty with which the mineral can be scratched • controlled by the strength of bonds between atoms

18. Cleavage

19. Cleavage • Way the mineral breaks or fractures • one direction of weakness, or in other minerals, 2, 3, 4, or as many as 6 may be present • determine the angular relation between the resulting cleavage surfaces • perpendicular • acute • obtuse

20. www.ironorchid.com/minerals/

21. From:geology.csupomona.edu/alert/mineral/minerals.htm

22. Streak

23. color of a mineral when it is powdered crushing and powdering a mineral eliminates some of the effects of impurities and structural flaws Black - Graphite Black - Pyrite Black - Magnetite Black - Chalcopyrite Gray - Galena Limonite - Yellow-brown Hematite - Red-brown Streak

24. From:geology.csupomona.edu/alert/mineral/minerals.htm

25. academic.brooklyn.cuny.edu/geology/leveson/core/linksa/mineral_id...academic.brooklyn.cuny.edu/geology/leveson/core/linksa/mineral_id...

26. Luster

27. way a mineral’s surface reflects light metallic earthy waxy greasy vitreous (glassy) adamantine (or brilliant, as in a faceted diamond) Luster From:geology.csupomona.edu/alert/mineral/minerals.htm

28. www.ironorchid.com/minerals/

29. Habit (Crystal forms and shapes) Hardness Cleavage Streak Color Luster Transparency Twinning Fracture Specific Gravity Associated Minerals Fluorescence Magnetism Odor Feel Taste Solubility Reaction to acids Radioactive minerals Meteoritic minerals Properties of minerals

30. Color From:geology.csupomona.edu/alert/mineral/minerals.htm

31. Crystal shape six crystal systems governed by the mineral's internal structure triclinic monoclinic orthorhombic tetragonal hexagonal isometric Habit From:geology.csupomona.edu/alert/mineral/minerals.htm

33. Specific Gravity • specific gravity • ratio of mineral density to the density of water • similar to weight • density • ratio of the mass of a mineral to its volume

34. academic.brooklyn.cuny.edu/geology/leveson/core/linksa/mineral_id...academic.brooklyn.cuny.edu/geology/leveson/core/linksa/mineral_id...

35. academic.brooklyn.cuny.edu/geology/leveson/core/linksa/mineral_id...academic.brooklyn.cuny.edu/geology/leveson/core/linksa/mineral_id...