6 materials from which idols were made as found in Daniel 5

Daniel 5:4
As they drank the wine, they praised the gods

of gold
and silver,
of bronze,
iron,
wood
and stone. 

Daniel 5:23

Instead, you have set yourself up against the Lord of heaven. You had the goblets from his temple brought to you, and you and your nobles, your wives and your concubines drank wine from them. You praised the gods

of silver

and gold,

of bronze,

iron,

wood and stone,

which cannot see or hear or understand. But you did not honour the God who holds in his hand your life and all your ways.