JEO253-Min-Pet Assoc. Prof. Meral Dogan Dr. Dogan’s homepage Lectures 3

1. JEO253-Min-Pet Assoc. Prof. Meral Dogan Dr. Dogan’s homepage Lectures 3

2. Lab Syllibus Lab #1: Measurement of Physical Properties of Minerals. Lab #2: Introduction to the lattice, unit cell, and Miller indices. Crystal systems, classes, and forms. Lab #3: Crystal systems and crystal classes (continued). Lab #4, 5 and 6: Tectosilicates, Phyllosilicates, Inosilicates, Cyclosilicates, Sorosilicates,and Nesosilicates Lab #7: Carbonates, Halides, Phosphates, Sulfates carbonates Lab #8:Native elements, oxydes and hydroxytes Lab #9:Magmatic rocks Lab #10:Magmatic rocks Lab #11:Sedimentary rocks Lab #12: Metamorphic rocks

3. Mineral idendification • Renk-Color • Parlaklık-Luster • Transparency (or diaphaneity) • Kristal sistemleri-Crystal Systems • Olusum formlari-Technical Crystal Habits • Descriptive Crystal Habits • Ikizlenme-Twinning • Dilinim-Cleavage • Kırılma-Fracture • Sertlik-Hardness • Specific Gravity • Cizgi rengi-Streak • Birlikte bulundugu mineraller-Associated Minerals

4. Color • Usually, we notice the color of a mineral first. Some minerals are easily identified by color because they are never any other color. For example, malachite is always green. • Keep in mind, however, that color by itself isn't enough to identify a mineral. Chemical impurities can change the color of a mineral without changing its basic make-up. For example, quartz in its purest form is colorless and clear as glass. Quartz with traces of iron becomes violet (amethyst). With traces of manganese, it turns pink (rose quartz). If quartz is exposed to radiation, it turns brown (smoky quartz).

5. Kuvars-quartz (SiO2)

6. Fluorit (CaF2)

7. labrodorite • color

8. çizgi rengi-Some minerals leave a streak similar to their natural color, such as cinnabar and azurite • Cinnabar Azurite

9. American Museum of Natural History

10. The terms used to describe luster (parlaklık) • (Metalik) Metallic -- example: gold ) • (Camsı)Vitreous (glassy) -- example: quartz, tourmaline • (Işıltılı) Adamantine (brilliant) -- example: diamond ) • (Reçine) Resinous (like resin or sap from a tree) -- example: sphalerite ) • (Yağsı) Greasy or waxy -- example: turquoise) • (İncimsi) Pearly -- example: talc) • (İpeksi) Silky -- example: asbestos) • (Toprağımsı) Dull or earthy -- example: bauxite)

11. Metallic -high reflectivity like metal • Galen (PbS) • Sulfit

12. Dull/earthy -shown by finely crystallized minerals • Hematit (Fe2O3) • Oksit

13. Mohs' Hardness Scale 1-Talc  2-Gypsum 3-Calcite 4-Fluorite 5-Apatite 6-Orthoclase Steel  file 7-Quartz 8-Topaz  9-Corundum  10-Diamond

14. Gypsum (CaSO4. 2H2O) • Jips • Sulfat

15. Calcite-CaCO3 • Crystal • (smooth • faces)

16. Elmas-Diamond • Crystal • Reflection

17. Common Objects and Their Hardness Values • 2.5Fingernail • 3.5 Penny • 5.5 Glass • 6.5 Steel knife • An unknown sample can not be scratched by your fingernail (2.5) but it can be scratched by a penny (3.5), then it's hardness is between 2.5 and 3.5. An example of a mineral that has a hardness between 2.5 and 3.5 is calcite (3).

18. Specific Gravity • is a special case of relative density defined as the ratio of the density of a given substance, to the density of water when both substances are at the same temperature. • Substances with a specific gravity greater than 1 are more dense than water, and those with a specific gravity of less than 1 are less dense than water.

19. MineralsDensitySpecific gravity • sulfur, graphite light 1-2 • gypsum, quartz medium 2-3 • fluorite, beryl medium -heavy 3-4 • corundum, most metal oxidesheavy 4-6 • native gold, platinum heaviest 19

20. Ağır mineraller-Heaviest mineral • Gold

21. Kristal sekilleri-Crystal forms • Cubic tetragonal hexagonal

22. Tuz-Halite (salt) (NaCl) • Cubic (intergrown)

23. Pirit-Pyrite (FeS) • cubic

24. Işınsal-Radiating habit • marcasite

25. Klivaj-Dilinim (Cleavages (images web site))

26. Fracture describes how a mineral breaks when broken contrary to its natural cleavage planes. • Chonchoidal fracture (quartz) is a smooth curved fracture with concentric ridges of the type shown by glass. • fibrous or splintery(tremolite), • Hackley (copper), is jagged fracture with sharp edges. • Irregular

27. Parting in Minerals • Parting is a property that often gets confused with cleavage. • There is good reason for that. Parting is a break along structural planes and is parallel to a possible face, just like cleavage. A good example is pyrite. However, parting differs from cleavage in some important ways. • It can not be found in every specimen as is true of cleavage for most every cleavable mineral. • It is not absolutely repeatable or reproducible as is cleavage down to theoretically the very atomic layers that cause cleavage. • Parting is caused by pressures that are applied to a crystal or by twinning. The pressure breaks the crystal on a plane of weakness.

28. Parting • With pressure parting the actual break formed long before the crystal was excavated from the ground and may be due to tectonic or isostatic pressures that have been forced on the crystal. • Most parting is seen as fracture lines that are incomplete or healed (the crystal continued to grow and sealed the break) and might appear as striations or planes of concentrated inclusions.