* The Mineral Madness Showcase and Sale at the Arizona-Sonora Desert Museum, 9 a.m. to 4 p.m. Saturday and 10 a.m. to 3 p.m Sunday, includes a "wheel of fortune" that kids can spin to win minerals. There also will be microscopes through which participants can examine tiny minerals. The show is free with admission to the museum, 2021 N. Kinney Road: $1.75 for ages 6-12, $9.95 for those older and free for those younger.

* Dig-It Mine Dump returns to the Flandrau Science Center and Planetarium's second annual "Flandrau Rocks! Rock Solid Science" exhibit next Friday through Feb. 28. Participants can find mineral specimens when they dig through the re-creation of a mound where miners tossed interesting but unwanted rocks. The museum on the University of Arizona Mall also will add more projects to its Crystal Construction Zone, in which participants can make crystal shapes of ever more complexity out of paper. Admission to the exhibit is $2 for ages 3-13, $3 for adults.

* Gold panner "Big John" Duhanich will relay mining lore and show equipment and gold nuggets at a Feb. 16 presentation at the Tucson Children's Museum, 200 S. Sixth Ave. Kids can pan for fake gold that Duhanich specially formulates. The presentation, 11:30 a.m. to 1 p.m., is included in the admission fee of $3.50 for children, $5.50 for adults, $4.50 for seniors.

* Elena Acoba