Mineral Identification Flashcards
1
Q
Mineral Definition
A
- naturally ocurring, inorganic, crystalline solid with a definite, but sometimes variable chemical composition
- must form in nature
- man-made crystals are not minerals (cannot tell them apart)
2
Q
Solids
A
- must be solid (liquids and solid are not minerals, mercury)
3
Q
Naturally Occurring
A
- must form in nature
- man-made crystals are not minerals (cannot tell them apart)
4
Q
Inorganic
A
- must be inorganic (no organic compounds, C bonded to H, not formed by living organisms)
- Coal is made from previously living organisms
- Can have carbon and not be organic
- Some animals can manufacture biochemical minerals to make shells and hard parts (made by animals but are not organic)
5
Q
Crystalline
A
- Minerals have atoms in a specific, orderly pattern or framework called a crystal lattice (have a distinct shape, quartz)
- Non-minerals have atoms or molecules in an amorphous solid are randomly arranged (no distinct shape, volcanic glass)
6
Q
Chemical Composition
A
- a definite but sometimes variable chemical composition
- each mineral has a set chemical composition (mixture of elements), although some elements may be swapped for other elements (dark vs white chocolate chip cookie)
- do not use colour to identify
7
Q
Colour
A
- highly variable among samples of the same mineral
- colours vary due to impurities in the crystal structure, microscopic inclusions of other minerals, or heat
- use only as a guide
8
Q
Lustre
A
- describes how a mineral reflects light
- metallic, vitreous (glassy), earthy, pearly
9
Q
Clarity
A
- ability to transmit light
- opaque, translucent, transparent
10
Q
Streak
A
- colour of the powdered mineral
- scraping rock along a porcelain “streak plate”
11
Q
Habit
A
- determined by chemistry
- shape a crystal will naturally develop as it grows (atoms added)
- cubic, prismatic, fibrous, platy, granular, massive (shapeless)
- mineral has a lot of space when growing, tend to form perfect crystals, limited shape = more irregular crystals)
12
Q
Euhedral
A
well formed crystal faces
13
Q
Subhedral
A
some crystal faces
14
Q
Anhedral
A
lacking crystal faces
15
Q
Fracture
A
- how a mineral breaks
- irregular fracture (rough, uneven) = Feldspar
- conchoidal fracture (circular depression) = Obsidian