Mineral Characteristics
• Naturally occurring• Inorganic (has never been alive)• Solid• Specific chemical composition (can be an
element or a compound)• Atoms are arranged in a regular crystal structure
Name some minerals…. Is coal a mineral? Salt? Sugar? Glacial ice? Natural gas? Diamond?
How Minerals Form
• Molten magma cools and crystallizes– If cooling is slow, large crystals form– If cooling is fast, small crystals form
• Minerals can form from solutions– Water can evaporate, leaving mineral crystals
behind– Minerals can precipitate from a saturated
solution
Mineral Identification
• Texture • How does it feel? (smooth, rough, glassy,
soapy, greasy)• Feel these minerals:– Quartz (smooth/glassy)– Graphite (greasy)– Talc (soapy)
Special Properties
• Taste (halite)• Smell (sulfur)• Magnetism (magnetite)• Double refraction (calcite-Iceland spar)• Effervescence—bubbles—in acid
(calcite/carbonates)• Fluorescence—glow in the dark (fluorite)• Iridescence—color changing (labradorite, bornite)
Mineral Groups
Sharing similar chemical composition:• Silicates: quartz, feldspar, mica• Carbonates: calcite, dolomite, azurite• Metal oxides: hematite, magnetite• Others: – Sulfides: pyrite – Halides: halite – Native elements: copper, silver, etc.
Top Related