TEACHING MINERALOGY IN THE CONTEXT OF THE ROCK CYCLE

Mineralogy is often a sophomore level course within the undergraduate geology curriculum, acting as a gateway between introductory courses and upper level petrology, structure, sedimentology, geochemistry, etc. It may function as a “weed-out” course, causing some students to abandon geology as a major and career. One reason is that early geology courses rarely deal with chemical concepts; also, introductory chemistry courses rarely deal with the properties of crystalline solids, but rather focus on gases, liquid solutions, atomic structure, & reactions. Mineralogy requires students to combine concepts of chemistry with those of geologic materials in order to understand naturally occurring crystalline phases. To best assist the students in learning new material, it is beneficial to make connections between new material and concepts previously learned. The conventional method of teaching mineralogy based on anionic groups does not readily lend itself to linking new concepts to ideas previously learned in introductory geology. To overcome this, minerals can be taught within the context of their common geological occurrence. The rock cycle thus provides an excellent thread throughout the entire course that can be used to weave new concepts together with those learned previously. Students are able to continuously refer to, draw from, and expand their understanding of fundamental information while learning new minerals and mineralogical concepts. I begin with minerals that commonly occur in silicate igneous rocks, and then discuss minerals that occur in hydrothermal veins, those produced by alteration near the Earth's surface, minerals common as aqueous precipitates, and end with minerals common in metamorphic rocks. Advantages: 1) better understanding of how minerals are produced by geologic processes; 2) better understanding of common mineral associations; 3) allows easier connectivity with previously learned material; 4) allows the instructor to spiral important content by reviewing minerals or mineral groups in a new geologic context. Difficulties: 1) deciding where to discuss certain minerals, e.g., chlorite & fluorite; 2) deciding on an appropriate depth for certain topics, e.g., amphiboles; 3) students may acquire misinformation about minerals being restricted in occurrence, e.g., calcite.