Download - 6th Grade-Ch. 5 Sec. 1 Classifying Rocks
Ch. 5 Sec. 1
Classifying Rocks
YouTube video-Bill Nye Rocks Rock Harder Song
Discover Activity-How do rocks compare? Pg. 144
Marble Shale Color Texture Which is harder?Which is denser?
rockmade of mixtures of minerals and other materials
geologists observe rock’s
1. mineral
composition
2. color
3. 3. texturetexture
1. mineral composition
•made of mixtures of minerals & other materials
rock-forming minerals
• about 20 minerals make up most of rocks of crust
2. color•gives clues to rock’s mineral composition
Granite is usually a light colored rock that has a high silica content.
Basalt is usually a dark colored rock that has a low silica content.
3. texture3. texture•Look & feel of a Look & feel of a rock’s surfacerock’s surface
3 Different Rocks
How are these rocks different from oneanother?
How are they similar?
grains•particles of minerals or other rocks
•gives rock its texture
grain shape• ex:
exploding stars crystal shapes rock fragments- smooth, rounded or jagged
conglomerate
Weathering Affects Grain Shape
grain pattern
• flat layers
• random
• banded
• nonbandedquartzite
Layered or random grains ?Layered grains
Nonbanded or banded grain patternbanded grain pattern
grain size• coarse grained= large & easy to see
• fine grained= grains so small- need microscope
• some have no visible grain
Diorite is _______ grained.
coarse
Types of Rock video clip
Make model of granite
Name that rock activity