This is one of the most unusual quartz crystals I've ever encountered, and I'm frankly at a loss to explain exactly how it formed. The photo does it no justice at all. Start by looking at the left side of the crystal. It is in the form of a four-sided prism. Three sides are relatively smooth, while the fourth shows diminishing faces.
All sides have triangular markings.
At the far left end is a termination that starts on two opposite sides of this odd prism. Now to the other end of the crystal, which is made up of multiple terminations of stubby hexagonal prisms. Apparently, what has happened is that the four-sided section is an expression of four of the termination faces, with all other faces suppressed. Nice smoky color for the whole thing, grading to colorless at the right end. There's even a nice round radiation spot of darker color.