Sean Murphy, Austin Gem and Mineral Society, demonstrates polishing rocks and minerals to very interested students. Margaret Baguio, from Texas Space Grant Consortium, brought authentic moon rocks and soil to the career fair. They were a big hit.     Everyone is interested in weather and the students are no exception as Bob Rose, LCRA meteorologist, talks about careers in weather prediction. The students are ready to watch the virtual reality models presented by Bureau Research Scientist Associate Dallas Dunlap.