Buyers usually follow the crude oil market in the CNSL (Cashew Nut Shell Liquid) trade as it is non edible. But this procedure is not always correct.
CNSL has its own uses in many commercial productions like cardanol, paints,rubber, plastics, resins, medicines etc.
It is also a cheaper substitute for costly edible oils in some non edible industrial uses, especially in India.
Then why the price difference between cashew shell and firewood is just 25% ?