What extrusive igneous rock type cooled so quickly that visible crystal grains never grew, and the rock is composed entirely of

Question

RUDIKE [14]

3 years ago

11

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

Geography

2 answers:

Len [333] · Answer 1 · 2022-02-06T20:42:30+03:00

Len [333]3 years ago

8 0

I think the answer is A

Kipish [7] · Answer 2 · 2022-02-06T19:28:07+03:00

Kipish [7]3 years ago

4 0

Answer:

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