The most important feature of the Sangam economy was flourishing trade with the Roman world.  

• The best account of Indo-Roman trade is given in the book called the Periplus of the Erythrean Sea, which was written in the first century CE by an anonymous author.  
• Major items of export to the Romans were the Indian products such as spices (included yavanapriya or pepper), perfumes, jewels, ivory and fine textiles (muslin especially), several precious and semi-precious stones like diamond, carnelian, turquoise, agate, sapphire, and so on, besides pearls, indigo, sandalwood, iron and steel cutlery. 

Source: Poonam Dahiya