I noted that the titanium herring was mentioned in this interview.
China has the world's largest reserves of titanium, and 14% of China's iron ore reserves contain titanium and vanadium. In fact, titanium is present on earth at a level of about 0.6% which places it in fourth place of structural metals after aluminium, iron and magnesium.
The role of China in the development of Javanese culture, technology, society and religion has been vastly underestimated.
This link will show exactly where early Javanese smiths got the material for their products, and when considered together with the nature of that material that they used will explain the development of pamor.
During the Early Classical Period there was high input to Javanese culture and society from the Indian Sub-continent, but during the East Jawa period Chinese involvement in Javanese affairs played an increasingly important role.