Question

Answer in one word:
(a) A rock with sharp edges​

Answer 1

Answer:

obsidian

Explanation:

Answer 2

ANSWER:

Obsidian is known as the rocks with sharp edges.

EXPLANATION:

It is a volcanic erupted lava rock. It has a glass view from outside. It also has a sharp edge used for various purposes. As it is made from lava its appearance is black. It is very hard and brittle in nature. Previously it was used as cutting tool, and piercing tool.

It was also used as surgical tool before. Its origin was dated as back as 1.5 billion years before. It was also used for hunting purpose as the arrow head. It was also polished to shine to be used as mirrors.