A detailed investigation of the relationship between crystal structure and chemical composition was conducted for a suite of kimberlitic garnets, and kimberlitic and non- kimberlitic ilmenites. The results for garnet showed clear trends of increasing unit cell with increasing calcium and chromium contents. Increases in unit cell occurred parallel to the divisions between major garnet types, making unit cell ineffective as a discrimination tool for diamond exploration, although it could have application to skarn exploration. Kimberlitic and non-kimberlitic ilmenites did not follow well defined trends and the two sources could not be distinguished by their unit cell dimensions.
This work also outlines several issues concerning the footprint of the incident X-ray beam ofthe Briiker D8 Discover at low glancing angles, and makes recommendations for future studies. In addition, a new method is reported that allows partially automated thin section mapping, providing modal mineralogy and 2D maps of the thin section
