Roman provinces traded among themselves, but trade extended outside the frontiers to regions as far away as China and India. The main commodity was grain. Chinese trade was mostly conducted overland through middle men along the Silk Road; Indian trade, however, also occurred by sea from Egyptian ports on the Red Sea. Also traded were olive oil, various foodstuffs, "garum" (fish sauce), slaves, ore and manufactured metal objects, fibres and textiles, timber, pottery, glassware, marble, papyrus, spices and "materia medica", ivory, pearls, and gemstones.