Although stone and wood were the principal materials on which they depended for their manufactures, they were all acquainted with several metals. Gold and silver were classed under the general name puvak, and distinguished as white and yellow; iron and copper were both known as ghigh, and distinguished also by their color. The metals formed an important element of their riches, and are constantly referred to as part of the tribute paid to the rulers. They were worked into ornaments, and employed in a variety of decorative manners.