300
Which of the following are characteristics of the common mineral known as quartz?
A. usually clear or cloudy, abundant in Earth's crust, quite hard
B. Usually dark and shiny, breaks off in sheets, resists heat
C. usually transparent or opaque, found in seashells, quite soft
D. usually shiny and golden, can rust, smells of sulfur
A. usually clear or cloudy, abundant in Earth's crust, quite hard