This silicon carbide, carborundum, crystal lattice model kit has 151 atoms; only $55.95. There are hundreds of SiC polytypes including 3C, 2H, 4H, 6H, 8H, 9R, 10H, 14H, 15R, 19R, 20H & 21H C, H and R which stand for cubic, hexagonal and rhombohedral symmetries. The ones most commonly used for electronics are 3C-SiC, 4H-SiC, and 6H-SiC. SiC occurs naturally as moisannite but is extremely rare.
See Related Products below for spare atoms & bonds that can be bought separately to build larger versions.