Final answer:
Tourmaline, topaz, and spodumene have different mineral formulae and crystal structures.
Step-by-step explanation:
The mineral formulae and crystal structures of tourmaline, topaz, and spodumene are as follows:
Tourmaline: The mineral formula for tourmaline can vary depending on the specific composition, but the general formula is (Na,Ca)(Li,Al)3(Al,Mg)6(BO3)3(Si6O18)(OH,F)4.
Topaz: The mineral formula for topaz is Al2SiO4(F,OH)2.
Spodumene: The mineral formula for spodumene is LiAl(Si2O6)
The crystal structures of these minerals vary as well. Tourmaline is a complex borosilicate mineral with a trigonal crystal structure. Topaz has an orthorhombic crystal structure. Spodumene has a monoclinic crystal structure.