Chapters 10 & 11 Rocks and Minerals Science, 8 th Grade Rocks and Minerals

Rocks and Minerals Science, 8 th Grade Rocks Earth’s crust is made of rock.rock Rocks are mixtures of minerals and sometimes other materials.minerals background image source:

Rocks and Minerals Science, 8 th Grade Studying Rocks When studying a rock sample, geologists observe the rock’s:geologists –Color click here for a rock color charthere –Texture –Chemical Composition

Rocks and Minerals Science, 8 th Grade Color Chart Quiz image source: Click the color on the color chart that best identifies the color of the rock above.

Rocks and Minerals Science, 8 th Grade That is not correct… Please click on the “Back” button and try again. Back

Rocks and Minerals Science, 8 th Grade Excellent! You have correctly identified the rock on the color chart. Click on the “Next” button to continue. Next

Rocks and Minerals Science, 8 th Grade Texture Most rocks are made up of grains, particles or minerals, or other rocks. Texture is the look that results from: –Size –Shape –Pattern of rock’s grains

Rocks and Minerals Science, 8 th Grade Grains Coarse-grained: large/easy to see Fine-grained: small, even microscopic –Click here for rock identification tables that include information on grain size.here Obsidian – A Fine-grained Rock image source: Sandstone – A Coarse-grained Rock image source:

Rocks and Minerals Science, 8 th Grade Grain Pattern Grains in rock often form a pattern. –Flat layers (strata) –Wavy, swirling patterns –Rows of beads –Random or no pattern Example

Rocks and Minerals Science, 8 th Grade Flat Layers (strata) Back

Rocks and Minerals Science, 8 th Grade Wavy, Swirling Patterns Back

Rocks and Minerals Science, 8 th Grade Rows of Beads Back

Rocks and Minerals Science, 8 th Grade Random or No Pattern Back

Rocks and Minerals Science, 8 th Grade Quick Forming Rocks Some rocks have no grain because they cooled too quickly when they formed.formed

Rocks and Minerals Science, 8 th Grade Rock Groups There are three groups of rocks: –IgneousIgneous –MetamorphicMetamorphic –SedimentarySedimentary Click on the links above to find the definition of each group of rock. Once you have reviewed these definitions online, click on the arrow to continue.

Rocks and Minerals Science, 8 th Grade Igneous Rocks Formed from the cooling of molten, or melted, rock PumiceGraniteBasalt

Rocks and Minerals Science, 8 th Grade Metamorphic Rocks Formed when existing rock is changed by heat, pressure, or chemical reactions GneissSchistPhyllite

Rocks and Minerals Science, 8 th Grade Sedimentary Rocks Formed when particles of other rocks, plants, or animals are cemented together SandstoneBrecciaSiltstone

Rocks and Minerals Science, 8 th Grade The Rock Cycle Click here for another illustration of the rock cycle.here

Rocks and Minerals Science, 8 th Grade Online Rock Cycle Activities The Rock Cycle –Click on the image below to access online resources and activities.

Rocks and Minerals Science, 8 th Grade

Minerals A mineral: –Occurs naturally –Is inorganic –Is Solid –Has a crystal structure –Has a definite chemical composition

Rocks and Minerals Science, 8 th Grade Minerals There are three thousand (3000) minerals. One hundred (100) minerals are common. Twenty (20) minerals make up most of the rocks of Earth’s crust (rock-forming minerals).

Rocks and Minerals Science, 8 th Grade Mineral Formation Minerals form through: –Crystallization of melted materials. –Crystallization of materials dissolved in water.

Rocks and Minerals Science, 8 th Grade Crystals Repeating patterns of a mineral’s particles that form a solid. –Click here for a crystal experiment from National Geographic.here

Rocks and Minerals Science, 8 th Grade Mineral Composition All minerals contain certain elements in definite amounts. Most minerals are compounds (two or more elements). Silver and gold are considered minerals.

Rocks and Minerals Science, 8 th Grade Mohs Hardness Scale The Mohs Hardness Scale ranks ten minerals from softest to hardest.Mohs Hardness Scale source:

Rocks and Minerals Science, 8 th Grade Ranking Minerals Minerals are ranked according to: Click on the word below for more information. –ColorColor –StreakStreak –LusterLuster –DensityDensity –CleavageCleavage –FractureFracture

Rocks and Minerals Science, 8 th Grade Color Back

Rocks and Minerals Science, 8 th Grade Streak Streak is the color of a mineral’s powder. Back

Rocks and Minerals Science, 8 th Grade Luster Luster is how shiny a mineral is. Back

Rocks and Minerals Science, 8 th Grade Density Density is mass per unit volume (specific gravity). Back

Rocks and Minerals Science, 8 th Grade Cleavage Cleavage is the breaking of a mineral along a regular line. Back

Rocks and Minerals Science, 8 th Grade Fracture Fracture is the irregular breaking of a mineral. Back

Rocks and Minerals Science, 8 th Grade Fluorescence Fluorescence refers to minerals that glow under ultraviolet light.

Rocks and Minerals Science, 8 th Grade Magnetism Magnetism occurs naturally in some minerals, such as magnetite.

Rocks and Minerals Science, 8 th Grade The End Click here for another online resource about rocks and minerals.here Click the arrow below to return to the beginning of this presentation.