spice trade a subject of political and cultural, as well as economic, interest.
In commercial terms, pepper has always been the most important of the spices, followed usually by cloves and nutmeg; but there are many others. Since their general characteristics are that they take up relatively little space, but are of considerable value, they have often been used as objects of barter against bulkier, less exciting but more necessary, goods such as rice and cloth.
In the early days of the trade, there was considerable mystery, fostered by those involved in the trade, about where some spices came from (usually S. or SE Asia). Their high value and this atmosphere of mystery combined to give these natural products something of the allure of precious metals. They were indeed sometimes used as currency.