How To Classify Rocks (below)!
To classify rocks you first need to record information you could use materials such as a camera or a notebook.Then you use sharp tools to get samples of the rock. Finally, you break open the rock to see what colors,textures and mineral composition the rock has. When you observe a rock sample you MUST look for the rock's mineral composition,color,and texture. The names of three major groups for classifying rocks are igneous rock,sedimentary rock, and metamorphic rock.Most geologists use the color and texture to find out what rock it is.
Geologists look at the shape,color and texture of the rock.They have many test to determine the rocks minerals.Some example are using a simple streak test or an acid test.
Texture and Color
Most geologist use the color and texture as a helpful source.Geologist call the particles of minerals grain.A rocks texture is the look and feel of the rock surface.
Grain size
In different rocks they have different grain sizes.The difference groups of grain sizes are #1 Fine grain,#2 Coarse grain #3 No visible grain.
Grain shape
In some rocks the grain result from the shape of the crystal that from the rock. The two main grain shape are #1 Rounded grain #2 Jagged Grain.
Grain Pattern
Some rock have grain of different colors and bands.There are two colors of bands #1 Non banded #2 banded.
Three major Groups
Geologists classify rock into three major groups:Igneous Rocks,Sedimentary Rocks and Metamorphic Rocks.