Abstract by Peter Van Katwyk

Personal Infomation

Presenter's Name

Peter Van Katwyk


Brittany Scott

Degree Level



Brittany Scott

Abstract Infomation


Geological Sciences

Faculty Advisor

Steve Nelson


Differentiating halloysite and kaolinite using formamide in Hawaiian soils


Non-tuberculous Mycobacterium (NTM), which can cause several types of respiratory illnesses in humans, is found in the soils of the Hawaiian Islands.  Since the clay minerals halloysite and kaolinite are abuandant there, it is important to differentiate between them. The purpose of this research is to identify the amount of halloysite versus kaolinite amongst other minerals from Hawaiian soils in order to identify their relationship to the occurrence of NTM. Using X-Ray diffraction, the mineral composition of over 200 soil samples was determined. The tests were run with and without formamide, which expanded the structure of 7Å halloysite to 10Å, allowing us to measure the halloysite to kaolinite ratio in each soil. For 86 samples investigated, 78 samples contained 100% kaolinite in the clay fraction. Eight samples, originating from various islands, contained halloysite. Of these 8 samples, 2 contained more than 70% halloysite and the other 6 contained less than 50%.In general, halloysite appears to be relatively uncommon across the islands.However, the complete data set will be used to examine mineralogical relationships between NTM positive and negative soils