Which of the following rock types are not comprised mostly of minerals.
A)limestone and rock salt
B)coal, obsidian, and pumice
C)sandstone and conglomerate
D)granite and basalt

Question

Quizplus · Accepted Answer

Coal is mostly comprised of organic matter, while obsidian and pumice are volcanic glasses and do not have a crystalline mineral structure. Therefore, all three of these rock types are not mostly comprised of minerals.

Which of the Following Rock Types Are Not Comprised Mostly