This is a present I have just received from my pen pal who lives in San Francisco. She often visits her relations in Hawaii and the book mark comes from the Honolulu Museum of Arts which was built between 1925 and 1927. The pattern on the bookmark represents the art deco air vents in the museum. It is made out of metal and is very shiny which you can't really see on my photo.
When I received that bookmark it came with a letter and the evelope had been opened. I'm surprised that the bookmark was still inside.