What are the characteristics of a mineral? (NISCC)

1
What are the characteristics of a mineral?
(NISCC)

• Naturally occurring
• Inorganic
• Solid
• Crystal system
• Chemical composition

2
Identifying Minerals

• Each mineral has its own specific properties used
  to identify it.

3
Color

• The same mineral can come in a variety of colors
• Ex. quartz
• Impurities other factors can change mineral
  appearance
• Color is not the best way to identify minerals

4
Luster

• Describes how a surface reflects light
• Ex. shiny/dull
• Metallic- minerals containing metals are often
  shiny

• Nonmetallic
• Vitreous- glassy, brilliant
• Silky-fibrous
• Resinous-plastic
• Waxy- greasy, oily
• Pearly- creamy
• Earthy- rough, dull

5
Streak

• Color of mineral in powder form
• Observed by rubbing a mineral against a piece of
  unglazed porcelain called a streak plate
• Streak doesnt vary like color is often
  different than a minerals color
• More reliable than color

6
Cleavage and Fracture

• Way a mineral breaks apart determined by
  arrangement of atoms
• Cleavage- breaks along flat surfaces
• Fracture- mineral breaks in an irregular way

7
Hardness

• Minerals resistance to being scratched
• Ranks minerals from softest to hardest
• Talc- softest known mineral
• Diamond- hardest known mineral

8
Hardness
9
Density

• Mass in a given space/ mass per unit volume
• D M/V
• Density remains same regardless of sample size
• Mass determined using balance
• Volume determined using water displacement method

10
Special Properties

• Fluorescence- minerals glow under ultraviolet
  light, ex. fluorite calcite
• Magnetism- ex. Magnetite
• Radioactive- ex. contain radium or uranium
• Effervescence- mineral fizzes (releases carbon
  dioxide) when in contact with hydrochloric acid,
  ex. calcite