Question

Which of the following is a rock composed of non-mineral matter?

Answer 1

Answer:

b) Coal

Explanation:

The rock from the presented list that is composed of non-mineral matter is the coal. This rock is actually composed of organic matter.

The coal is a sedimentary rock. Its basis is organic matter as mentioned. The organic matter has been provided by the trees that have died off, especially the ones from the Permian period.

When the trees died off, they were covered by natural materials that isolated them from the outside influences that would decompose them. Instead, they have been gradually buried deeper into the ground, being exposed to higher temperatures and pressure, which gradually, over the course of millions of years turned the organic matter and the chemicals with which it interacted into sedimentary rock, the coal.

The coal has been the main energy source for the industry, and it was extremely important for the technological advancement in the past few centuries.