What extrusive igneous rock type cooled so quickly that visible crystal grains never grew, and the rock is composed entirely of black silicate glass that easily shatters into sharp, knife-like shards?

(A) Obsidian

(B) Pumice

(C) Scoria

(D) Tuff

Question

Geography

Nyasia Flores

8 April, 19:01

What extrusive igneous rock type cooled so quickly that visible crystal grains never grew, and the rock is composed entirely of black silicate glass that easily shatters into sharp, knife-like shards?

(A) Obsidian

(B) Pumice

(C) Scoria

(D) Tuff

+5

Answers (2)

Know the Answer?

Lawson Dorsey · Answer 1

I think the answer is A

Zain Parks · Answer 2

A. Obsidian

Explanation:

It fits the property described in the question.

It cools so fast that no visible crystal or grain could form. It has high silica Composition, black and glassy. It is also used to make tools with sharp edges

What extrusive igneous rock type cooled so quickly that visible crystal grains never grew, and the rock is composed entirely of black silicate glass that easily shatters into sharp, knife-like shards?(A) Obsidian(B) Pumice(C) Scoria(D) Tuff

What extrusive igneous rock type cooled so quickly that visible crystal grains never grew, and the rock is composed entirely of black silicate glass that easily shatters into sharp, knife-like shards?

(A) Obsidian

(B) Pumice

(C) Scoria

(D) Tuff