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Flashcards in Mineral Identification Deck (20)
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1

Metallic

opaque

reflects most light

2

Resinous

dull

waxy

3

Pearly

greasy

reflects some light

4

Adamantine

brilliant

high refractive index

ex: diamond

5

Vitreous

glassy

low refractive index

ex: quartz

6

Prismatic

well-developed pyramidal prism faces

7

Columnar

irregular prism faces

8

Acicular

needle-like

9

Botryoidal

rounded

blob/bubble-like

10

Tabular

flattened columns

plate-like

11

Stellate

radiating sprays of needles / fibers

12

Fibrous

parallel fibers

13

Dendritic

tree-like

14

7 Mineral Properties

  1. Crystal form and habit
  2. Luster and transparency
  3. Color and streak
  4. Cleavage, fracture, and parting
  5. Tenacity
  6. Density
  7. Hardness

15

Transparency

May be opaque, transparent, or translucent

Luster is a reflectance property that depends on the transparency of a mineral

16

Luster

Reflectance property based on the transparancy of a mineral

opaque minerals may appear metallic or dull and resinous

transparent minerals with a high RI appear brilliant and adamantine ex: diamond

transparent minerals with a low RI appear glassy and vitreous ex: quartz

17

Cleavage, Fracture, and Parting

In most xtals, atomic bonding is not of equal strength in all directions therefore, the weaker bonds tend to break along crystallographic directions giving them a fracture property that reflects the underlying structure.

perfect cleavage results in regular flat faces

less well-developed cleavage is imperfect 

very weak cleavage is parting

if a fracture is irregular, it is hackly

conchoidal is an irregular scallop-shape

18

Tenacity

The ability of a mineral to deform plastically under stress

brittle - does not deform

sectile - may be cut with a knife

ductile - deforms readily

19

Density

g/cm3

density = mass / volume

20

Hardness

Mohs scale of Hardness

Approx. linear scale of standard minerals

  1. Talc
  2. Gypsum
  3. Calcite
  4. Fluorite
  5. Apatite
  6. Orthoclase
  7. Quartz
  8. Topaz
  9. Corundum
  10. Diamond