Crystal facets (faces) are described by three numbers called "Miller indicies."
For a "cubic" crystal, such as silicon, you find the Miller indicies of a facet by figuring out the vector perpendicular to that facet.
The vector (0)x + (0)y + (1)z is perpendicular to the facet on top, so this is a (001) facet.
The facet that starts at the front is perpendicular to (1)x+(-1)y+(1)z making it a (1-11) facet.
Drag the mouse across the model (repeatedly) to rotate it.
Restore its position with the reset button.
