Crystal Structure of Metals

Crystal Structure of different metals are as follows:

BCC

Fe, most steels, Cr, W, Mo, Ta

FCC

Al, Cu, Ni, Au, Ag, Pt, Pb, some stainless steels

HCP

Ti, Mg, Zn, Cd, Co, Zr

In general. Metals have close packing and large atomic mass, hence their density is higher than the other materials. Broadly, the densities of different classes of materials are grouped as:
ρ_metal [2-20 Mg/m³] > ρ_ceramic [1.5-4 Mg/m³] > ρ_polymer [0.02-2 Mg/m³]