The local copper ores often occur together with gold and silver.

However, no copper ores have been found with these amounts of tin oxide.

The river was named for the copper ores which could be found along the lower river.

Child labour is also present in mines of lead, zinc and copper ores.

It has been mined for centuries and is one of the most profitable copper ores.

Starting in 1957, the mine produced nickel and copper ores from an underground operation.

The Vučedol culture exploited native copper ores on a massive scale.

The region is one of the world's largest suppliers of nickel and copper ores.

They used to mine copper ores.

Often, the nature of the gangue is important, as clay-rich native copper ores prove difficult to liberate.

The company also signed its first contract for work in Africa, sending equipment and a crew to provide drilling for copper ores.

Silver must have come from silver-bearing lead and copper ores but there is no evidence of mining lead itself until the late Saxon period.

The modern era started when the American engineer Bradley finally developed a method of working low grade oxidised copper ores.

While it is produced mainly from sphalerite, it is also found in silver, lead, and copper ores.

The earliest brasses may have been natural alloys made by smelting zinc-rich copper ores.

It occurs as an uncommon oxidation mineral in vanadium bearing hydrothermal copper ores.

He famously concluded: "the copper ores are not only of superior quality, but also that their associations are such as to render them easily reduced."

Potentially valuable minerals include uranium and copper ores and coal and salt deposits.

Reserves at the Shubinskoe deposit were estimated to be 1.5 Mt of lead-zinc and copper ores.

These may be "natural alloys" manufactured by smelting zinc rich copper ores in redox conditions.

Most cadmium used in the United States today is obtained as a byproduct from the smelting of zinc, lead, or copper ores.

The list of interesting minerals, mostly created by weathering of copper ores, also includes azurite and malachite.