Lead

An unusually hard lead mineral is plattnerite (PbO₂). Its crystal structure is the rutile structure. Just like it is the case with the corresponding minerals of leads group members (carbon excluded):

• Plattnerite PbO₂ (Mohs 5.5; ~9.63g/ccm)
• Cassierite SnO₂ (Mohs 6-7; ~7.1g/ccm)
• Argutite GeO₂ (Mohs 6-7; ~6.28g/ccm)
• Stishovite SiO₂ (Mohs 9-9.5; 4.287g/ccm)

Interestingly in earths crust lead (Pb) is a bit more common than tin (Sn) which in turn is more common than germanium (Ge). Despite this is going upwards the periods of the periodic table. Normally for groups this is the other way around. Higher periods mean

Lead may be on the border of its level of abundance/scarcity that allows for its use of mass structural element. But given its toxicity when getting leached out in some way one might want to go for other options like the element above tin (Sn).

From a mechanical perspective the biggest reason for the use of lead would likely be its high density.

Related

• Other members of the group: Lead, Tin, Germanium, Silicon, Carbon
• Chemical element