<span>The minerals that make up </span>rocks<span> have defined chemical </span>compositions<span> and rigid atomic structures. When sunlight strikes the </span>rock's<span> surface, the </span>composition<span> and atomic structure of the different minerals control the wavelengths they absorb or reflect.</span>
There are four states in the U.S. that begin with "I": lowa, Illinois, Idaho, and Indiana
