What are the ores contaminated with impurities known as? 

Gaunge 

The correct answer is option 4. Gaunge.

The ores contaminated with impurities are known as gangue. Gangue refers to the rocky or worthless material that surrounds, accompanies, or is mixed with the desired mineral in an ore deposit. These impurities typically include non-valuable minerals, such as quartz, calcite, clay minerals, and various silicates. Gangue is separated from the valuable mineral during the process of ore extraction and concentration. So, the correct answer is Gangue.