There are hundreds of crystal faces on this specimen, and the crystals are perfectly parallel to each other, so they reflect the light in a brilliant display that lights up these faces like an array of flashing mirrors.  In Brazil, this form of quartz is called jacaré, which is the Portuguese word for alligator.  This colorful term was chosen because the parallel faces, which are higher than the surrounding quartz, looks like the back of a submerged alligator!  The specimen is a very pale smoky color, and all of the crystals are extremely sharply formed and mirror smooth.