minerals are: * solid, inorganic materials that form naturally on or beneath the e’s surface
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Minerals Are:* Solid, inorganic materials that form naturally on or beneath the E’s surface.
•Have a definite chemical composition.
•Usually solid. High temp. inside the Earth can melt them.
• Inorganic – not made from things that were once alive.
•Naturally Occurring – not man-made. Formed as a result of processes in the natural world.
•Have definite crystal structure – repeating patterns of a mineral’s atoms.
•Use a magnifying glass to see “flat edges” where breaks have occurred.
•Definite Chemical Composition –
Each type of mineral has the same proportions of the same elements.
How Mineral Form
• Most minerals form when molten material (magma) cools and hardens inside Earth or on the surface
• Some form when a solution evaporates on Earth’s surface– Ex. Halite NaCl
How Minerals are Formed
• If magma or lava cool slowly then large crystals will form– Ex. Quartz
• If magma or lava cool quickly the small crystals will form– Ex. Feldspar
Identify Minerals•Look at the Properties – characteristics that make that mineral different from other minerals.
Ways to Identify:•Hardness•Color•Streak•Luster•Cleavage•Density
Identifying Minerals
• Hardness- use Moh’s hardness scale p 95 of textbook
Color
• Not good to use.
• Several minerals come in different colors.
Streak
• - color of the mineral’s powder found when the mineral is rubbed on a piece of tile
Luster• - how a mineral reflects light: glassy,
pearly, metallic, and earthy
Cleavage & Fracture
•Cleavage: split apart easily along flat surfaces.
•Fracture: irregular surface where it breaks
Cleavage
Fracture
Density
• Density = mass/volume
• Use a balance to find mass in grams
• Use a graduated cylinder to find volume in milliliters
Other Properties:• Chemical reaction: fizzes with vinegar (Calcite)
• Transparent – can see through it
• Opaque – pearly, cloudy
• Magnetic * High Mass