Tourmaline usually is crystalline and that is its most identifying feature Shaman Mr Lee's signature pic is a good example of what to look for when identifying tourmaline though the most common forms are black in color. What I'm seeing is a quartz specimen with lateral striations that put me in mind of agate. However because the crystals are so large it does not fall under agate~ more of a compressed and layered rock crystal formation. That you have clean breaks and a smooth surface lends to compressed rock crystal.
Your showing ya have a good eye though Tourmaline will look similar to that when its broken and in large pieces.