Nah, I highly doubt it. BJTs aren't even sandwiches like you would think. Each piece of the semiconductor is entirely one solid crystal lattice structure, with the three different dopings. And sand as I know it refers to all transistors, not just BJTs. Sand = silicon dioxide with impurities, silicon is the most commonly thought of semiconductor (Group IV, can also have Group III-V, and I think even Group II-VI semiconductors), and purified silicon dioxide was originally used as the insulating layer between the gate and the bulk of MOSFETs.