limestone granite basalt gypsum
I gave my students this multiple choice question: Most sand is made of quartz and has a white or brownish color. A student walking on a beach in Hawaii notices the sand is black in color. This sand most likely came from which type of rock?

Only one answer is correct among these 4 choices:
- limestone
- granite
- basalt
- gypsum

Could you tell me which one is correct?

basalt