The global trade of South East Asian diamonds and gems in the early modern period has attracted the attention of a number of scholars in the last decades, who have mostly focused on the way the European East India Companies, such as the Dutch, the Portuguese and the English conducted private trade in gems based on those companies’ archival records. Diamonds and gems fitted perfectly into the range of commodities that were easy to carry, move and smuggle with and were one of the most luxurious and valuable items circulating during the seventeenth and eighteenth centuries’ flows of commodities being accessible to only the privileged. While the global trade of diamonds and gems in the early modern period was largely conducted by the East India companies of Europe, it was also a niche commercial activity for Armenian merchants from New Julfa and their counterparts from the Sephardic trade diaspora in Europe. Although scholarly work on the involvement of Sephardic Jews and the East India Companies in early modern global gem trade is sufficient, scholarly work on New Julfa Armenian merchants’ involvement in it is almost next to nothing. With representatives and agents always on the move from the Russian Empire to Bandar Abbas, Izmir, Aleppo, Amsterdam, London, Venice, Livorno all the way to Surat and other cities, the Minasian firm of professional gem merchants became one of the most influential family firms involved in seventeenth and eighteenth centuries’ diamond and gem trade. By looking at around forty lengthy and obscurely written commercial letters of this firm dating from 1684-1700 mostly sent from New Julfa (Isfahan) to all the cities covered by the network of agents of the Minasian family firm, my paper sheds light on the inner workings of a global early modern family firm of gem merchants. On the example of the Minasians, it argues that the exchange of European corals and Indian diamonds was a vital part of early modern gem trade among Armenian New Julfa merchants and beyond. Additionally, my paper argues that the exclusive involvement of this firm and its representatives in luxury trade of gems gave them the opportunity of navigating through economic, political and religious worlds of Europe and Asia thanks to their mobility, knowledge, mediation skills, flexibility, but most importantly business dealings with the upper echelons of the business world and religious hierarchy.