In Harappan cities most of the things that have been found by archaeologists are made of stone, shell and metal, including copper, bronze, gold and silver. Copper and bronze were used to make tools, weapons, ornaments and vessels. Gold and silver were used to make ornaments and vessels. The Harappans also made seals out of stone. These are generally rectangular and usually have an animal carved on them. The Harappans also made pots with beautiful black designs. Archaeologists have also found spindle whorls, made of terracotta and faience. These were used to spin thread.