Defination of Marketable :

Marketable mean Articles in crude or elementary form are not dutiable as they are merely intermediate products and are not goods. Various courts held that it would be necessary to find out whether the goods are known in the market as separate, distinct and identifiable commodities.

In a leading case of Ion Exchange India Ltd.  v. C.C EX1999(112 0 ELT-746 the SC has held that mere specification of an item in the Central Excise Tariff is not sufficient in the absence of the marketability test.