Both obsidian and pumice are formed from which of the following?

- Ocean sediments

- Earthquakes

- Flooding

- Volcanoes

option D = volcanoes

Explanation:

Obsidian:

It is igneous rock. It is made when molten rock material cool very rapidly in such a way that atoms could not arrange themselves and acquire amorphous form. It is also called mineraloid.

1. Mostly it is found in black color but it could be present in green or brown color.

2. In the form of glass obsidian are unstable and start to crystallize.

3. Obsidian are commonly found in New Zealand, Hungry, Russia, Canada, Italy, Argentine, Japan, Chile, Kenya, Peru and United States.

4. older obsidian can not be found because these glassy rocks destroyed very rapidly.

5. Obsidian are used in surgical tools for cutting.

6. obsidian are also used in jewelry.

Pumice:

pumice is volcanic rock. it is formed from the lava having high amount of gases and water content. the gas escape and frothy lava cool very rapidly and form very lighter rock material, called pumice.

1. it is lighter in color because of high content of silica.

2. its crushing material produce fine powder, called volcanic ash.

3. its density is very low that's way it floats on the surface of water.

4. it is used in the manufacturing of cement and also in pencil erasers.

5. it is found in Greece, Italy, Chile, Turkey, Russia, Tran, Syria ans United States.