1. High-grade your sample to the <2 Ám fraction. Follow the flow chart above and the procedures described both in lab and in Moore and Reynolds (pages 204-225). Samples are also available for testing from the Clay Minerals Society Source Clay Project. Your approach to sample preparation and treatment(s) will be unique, depending upon the composition of the original sample. A bench in the geochemistry laboratory (room 303) and in the rock prep lab (room 305) have been reserved for the semester as a work area for this class. Please keep these areas clean. If you use glassware, clean it and put it back. Chemicals, ovens, ultra-sonic device, etc. are around the labs.
2. Collect randomly-oriented X-ray diffraction patterns for the bulk sample and for the <2 Ám fraction. Use the following scan parameters:
Whole rock - random:
Start: 3░ 2θ End :70░ 2θ Step increment: 0.01░ 2θ Scan rate: 5░ per minute
< 2 Ám - oriented:
Start: 2░ 2θ End :45░ 2θ Step increment: 0.01░ 2θ Scan rate: 5░ per minute
3. For each diffractogram determine the peak positions using what every approach you feel is appropriate (cursor, second derivative, or profile fitting). Transfer your data files to the XRD lab laptop. Make electronic file versions of graphics.
4. Be prepared to discuss your results in class.