Several studies have shown that there is a negative impact of perceived risk on trust and on the online purchasing behaviour of buyers. Other research suggests a positive impact. However, these relationships have been suggested by using evidence obtained from the purchase of inexpensive, uncomplicated, and hence low risk products such as books, compact disks (CD’s, DVD’s), or clothing. Exploring whether such associations could be generalised within the complex, costly high risk and credence products such as gemstones has not been examined. This gap in the literature was addressed in this study. The results of the study suggest that perceived risk and trust are significant determinants of the online purchasing behaviour of gemstone buyers. The study also shows that the type of Internet marketing strategy used by the seller (the place strategy) and the buyer’s privacy, and security concerns influence a buyer’s perceived risk to purchase gemstones online. Furthermore, Internet fraud protection has been found to be the only significant factor that has an influence on the buyer’s trust to purchase gemstones online. These results have implications for the literature, and all sellers and consumers.