Materials

1. plants

1.1. such as

1.1.1. wood

1.1.2. cotton

1.1.3. rubber

2. ground

2.1. such as

2.1.1. tin

2.1.2. gold

2.1.3. granite

3. man-made

3.1. nylon

3.2. glass

3.3. plastic

3.4. styrofoam

4. Animals

4.1. silk

4.2. wool

4.3. leather