Gather your kids’ rocks, sticks, shells, and other found natural urban curios (that’s not an oxymoron), and lug them to the annual Identification Day at the American Museum of Natural History. This is no Antiques Roadshow knockoff (“We preceded them,” quips Elaine Charnov, director of public programs), so don’t expect monetary appraisals. Instead, watch museum scientists attempt to identify all manner of knickknacks. “There’s always the human desire to have understanding and appreciation of monetary value, but we’re an educational institution. It’s about sharing scientific knowledge.” This doesn’t mean people haven’t shown up with minerals and gems as if the museum were Sotheby’s. No matter. Families have also brought “extraordinary cultural objects and occasional paleontological finds,” including arrowheads dug fresh from Long Island backyards. The scientific staff will help “illustrate the difference between a formed arrowhead and a stone that has been washed away by the elements and appears to look like one.” No lawn to dig in? Seedpods and feathers (preferably not plucked from live pigeons) are great bring-ins. Empty-handed visitors can still watch the geologists and botanists solve mysteries. The museum will link the event to its current “The Horse” exhibition by showcasing horseshoe crabs and seahorses and having a Brooklyn College archaeologist—with Viking-era horse bones—on hand to illustrate evolution. A Breyer Horse Collection expert will discuss horse collectibles. Try bringing in junior’s My Little Pony to see if the experts can identify the species (Clydesdale with a bad dye job?). Just don’t ask them what it’s worth.