What properties could enable gold to be made into rigs; copper into fine wire; diamond to cut glass and clay t

Answer 1

they all contain minerals

Answer 2

Gold can be made into rigs because it is soft and is easily shaped.
Copper is also soft and can be stretched into fine wire. It is more readily available that gold and conducts electricity almost as well as gold. That's why copper is the industry preferred metal for wire.
A diamond's hardness enables it to cut glass.

Answer 3

You can make rigs out of gold, but steel is much cheaper, and less likely to be stolen.

I've never used a diamond to cut clay. Try a spade.