Answer:
C. The planar faces that form the object are crystal faces that grow when the crystals grew into a void.
Step-by-step explanation:
Quartz is considered the most abundant mineral on earth. Its best known form is quartz crystals, similar to broken glass pieces. Quartz formations are part of a geological process that can take thousands of years. Quartz stones are mainly composed of Silicon Dioxide (SiO2), being present in all types of rock formations on the planet, whether igneous, metamorphic or sedimentary. Quartz is sold as six-sided elongated objects with a sharp end, this shape is caused because the flat faces that form the object are crystal faces that grow when crystals grow in a void.