The palm-sized rocks look perfectly ordinary, at first.
Yet with just a few dabs of paint and some kind words, they're transformed into the hide-and-seek reward of a treasure hunt that's spreading across the north metro area.
For months, the rocks have been popping up in little libraries, on park benches and outside shopping centers, largely thanks to an area Girl Scout troop that has painted and hidden hundreds of them since April.
Their efforts are part of the Kindness Rocks Project, a movement that got its start on the East Coast two years ago and has now spread across the globe, with painted rocks popping up from Europe to Australia.
They often bear simple messages, like "Be Kind" or "You are loved." A small, wordless picture may also convey encouragement.
"When somebody finds a beautifully decorated rock, it can make them happy," said 9-year-old Alyx Gerhart, a member of Girl Scout Troop 16984. "We're spreading joy."
The idea is that even an unassuming rock can offer a sign of human connection and inspiration. Those who find the rocks are then encouraged to paint and hide their own.
"It's not really about the rocks," said project founder Megan Murphy, a 49-year-old life coach who lives on Cape Cod in Massachusetts. "It's all about connecting people with one another."