Useful Crystals

YBCO Superconductor, YBa2Cu3O7 
blue = Y, orange = Cu, white = O, Ba invisible here
Europhys. Lett. 3, 1301 (1987)

Cadmium Selenide Semiconductor, CdSe
orange = Cd, white = Se
Phys. Rev. B 48, 4335 (1993)

BBO Non-linear Optical Material, BaB2O4 
yellow = Ba, blue = B, white = O
Cryst. Growth Des. 7, 1561 (2007)

Neodymium Magnet, Nd2Fe14B
orange = Nd, blue = Fe, white = B
J. Appl. Phys. 78, 1892 (1995)

Zeolite A, Al96Ca48O384Si96 
yellow = Si, green = Al, white = O, Ca not shown
Acta Crystallogr. B56, 766 (2000)

Dry Ice, CO2 
dark gray = C, white = O
Acta Crystallogr. B36, 2750 (1980)

Aluminium, Al
J. Chem. Phys. 3, 605 (1935)

Iron, Fe
J. Chem. Phys. 3, 605 (1935)

Table Salt, NaCl
blue = Na, white = Cl
Am. Mineral. 89, 204 (2004)

Table Salt at High Pressure, NaCl7 
blue = Na, white = Cl
Science 342, 1502 (2013)