Brain Teasers 2, a collection of tricks, games and puzzles that encourage problem-solving skills, continues through Sunday, May 8. Dangerous Beauty: Minerals of the Hindu Kush, featuring rare and valuable gems from regions of Afghanistan and Pakistan now in the news, continues through Thursday, June 30. Hours are 10 a.m. to 3 p.m., Monday through Friday; 6 to 9 p.m., Friday; 10 a.m. to 9 p.m., Saturday; and 1 to 4 p.m., Sunday. $7.50; $5 child age 4 to 15; free child younger than 4; $2 Arizona college student with ID; $2 discount to Cat Card holder. Call or visit flandrau.org for more information.