X-ray Analysis of Sand
This is an x-ray diffraction analysis of six sand samples and comparison with hand specimens.
This exercise is designed for a mid/upper-level undergraduate geology course on the principles of mineralogy.
Skills and concepts that students must have mastered
Students should have knowledge of basic chemistry and of minerals equivalent to what they would learn in an introductory geology class.
How the activity is situated in the course
This activity is the 18th of 36 mineralogy exercises and is used around the middle of the course.
Content/concepts goals for this activity
- Learn practical aspects and limits of X-ray diffraction.
Higher order thinking skills goals for this activity
- Learn to critically evaluate analytical results.
Other skills goals for this activity
Description of the activity/assignment
This is an x-ray diffraction analysis of six sand samples and comparison with hand specimens. Students look at each of the six samples under the binocular microscope and note such useful properties as number of minerals, cleavage/fracture, color, shape, grain size, roundness, and degree of sorting. Then they grind up small amounts of each sample and mount them on glass slides for X-ray. Students write all sample descriptions and X-ray analysis results in their lab notebook. Then they identify the minerals in each sample, determine where they are from, and write a report summarizing all results.