I-Minerals' Helmer-Bovill property is primarily underlain by the Thatuna granodiorite, and the Latah formation, a sedimentary sequence of sands and clays. Within this environment, I-Minerals has identified two types of industrial mineral deposits:

1. Unweathered Thatuna granodiorite: feldspar - quartz deposits
2. Weathered Thatuna granodiorite: kaolinite, halloysite, potassium feldspar and quartz deposits (also known as "primary clay")

These deposit types are both related to a unique border phase of the Thatuna granodiorite that is very low in iron and other elements that are detrimental to the production of high quality industrial mineral products.