Some specimens have been reported in copper, lead, or clay.

It was in wheat field gold, chocolate brown and copper.

They were known for their work in ceramics, copper, and gold.

I see the beauty in gold, silver, copper and oil.

Fully made with modern components, the dome is in natural copper.

In copper, for example, the mean free path is 40 nm.

He took up a land grant of 100 acres which happened to be rich in copper.

The mountain is said to contain $500 million in gold, silver and copper.

There should be a break in copper between this strip, and the main ground plane of the circuit.

The first year of production, 1964, was minted in 90% silver and 10% copper.