New Delhi, 18 August (NNS): The prices of cumin declined by Rs 500 to Rs 20500 per quintal because of the weak buying from the stockists. Before this, the prices have gone down by Rs 200 per quintal. There were around 6000/7000 bags of cumin reported to arrive and the prices held stable at the same level of the previous day. The active contract prices ascended by Rs 220 or 1.17 percent to Rs 19095 per quintal because of the higher speculative buying. There is possibility of temporary improvement in the spot coriander prices during the near future.