This article situates the collecting practices of museums of natural history in the nineteenth and early twentieth centuries in dialogue with similar practices amongst societies in the Pacific by focusing how European curators, dealers in natural history and Pacific Islanders shared a common fascination with spondylus shells. In particular, this article examines the processes for turning spondylus shells into unique or duplicate specimens. Spondylus shells were crucial for regulating gift and commercial exchanges in the societies of both regions. Famously, the anthropologist Bronisław Malinowski claimed that these shells were an essential element of the gift-based kula exchange, which helped him distinguish Western capitalist society from less developed societies without commercial trade. Yet spondylus shells were also collected and exchanged as gifts amongst British and European naturalists in this period, performing the same roles as in Melanesia. In addition, such gift exchanges could only come into being thanks to the actions of commercially motivated dealers, located both in the Pacific and in Europe, who were the suppliers of these shells both to Melanesian participants of the kula and to Western natural historians and collectors. These observations call into question earlier arguments that equate modernity with the rise of commercial capitalism. It is instead claimed that commercial and gift exchanges were intricately connected and reliant on each other throughout the period, whether in the worlds of Western museums or in Pacific archipelagos. The act of turning spondylus shells into unique or duplicate specimens was the key tool for regulating these exchanges.