The list of minerals that commonly form rocks is short. With a little practice you will recognize most of them when you see them. Descriptions of some of the minerals, as they look in rocks, follow Quartz is the last mineral to crystallize, so in igneous rocks it never has any definite shape. In rocks, it does not show flat faces. It is usually gray in igneous rocks; gray, white, yellow, or red in sedimentary rocks; and gray or white in metamorphic rocks. It has a glassy, or sometimes waxy, look to it. Hope this helps :)
