Rock Composition and Texture Identification

The video tutorial explains how to identify rocks by examining their texture and composition. It covers three main compositions: mafic, felsic, and intermediate, with a mention of ultramafic. Various textures are discussed, including glassy, porous, fine grain, coarse grain, and textures with two grain sizes. The tutorial analyzes several rock samples, detailing their textures and compositions, and guides viewers on how to classify rocks using a lab manual chart.

What are the two main factors used to identify rocks?

• Age and location

• Size and shape

• Texture and composition

• Color and weight

Which rock composition is not present in the collection discussed?

• Intermediate

• Mafic

• Ultramafic

• Felsic

Which texture is characterized by a shiny appearance?

• Porous

• Glassy

• Fine-grained

• Coarse-grained

What is the composition of rock sample number 50?

• Mafic

• Volcanic glass

• Intermediate

• Felsic

Which rock sample is described as having a texture with two grain sizes?

• Sample 53

• Sample 50

• Sample 51

• Sample 52

What is the texture of sample number 54?

• Coarse-grained

• Very coarse-grained

• Medium-grained

• Fine-grained

Which sample is described as felsic and medium to coarse-grained?

• Sample 57

• Sample 56

• Sample 55

• Sample 54

What is the composition of sample number 57?

• Ultramafic

• Intermediate

• Felsic

• Mafic

Which sample is described as mafic and coarse-grained?

• Sample 58

• Sample 59

• Sample 57

• Sample 56

How can you classify and identify the rocks using the lab manual?

• By their weight

• By their age

• By their color

• By their composition and texture