Professor Yoder collaborates with Dr. Jill Pasteris in the Department of Earth and Planetary Sciences at Washington University, St. Louis, MO . Their research involves the structure and stability of compounds in the apatite family of minerals. Calcium hydroxy apatite, the major constituent of bone and teeth, serves as a prototype for the study of the substitution of carbonate for the phosphate and hydroxide ions. The study should lead to a better understanding of the effect of carbonate and other anions on the solubility and structure of apatites and their use in the remediation of heavy metals.