As a perk for supporting the Safecast Kickstarter campaign, I received the Safecast Onyx Geiger counter. A Geiger counter is a radiation survey instrument used to detect alpha particles, beta particles, and gamma rays emitted from decaying atoms. Upon receiving my detector, I went in search of radioactive sources. Below are some photos and video showing some of the items I've come across.
"Fiesta Red" glazed Fiestaware gravy boat showing a high level of radiation, found in an antique shop in Santa Paula, CA
Vase and two glasses behind other glass antiques are Uranium glass (aka Vaseline glass)
Video of some Uranium glass marbles showing their radioactivity and their fluorescence under UV light
Uranium glass teacup and saucer
Glass jar miss-labeled as "Vaseline glass", but no Uranium is detectable only low level background radiation of ~53CPM
Naturally occurring Potassium-40 detectable in a large bag of Potassium Chloride (used to replenish water softeners)
Some low level radioactive materials are available for purchase online. In addition to the above items, I've been able to purchase a self illuminating tritium vial, radium watch hands, and thoriated welding rods all which contain a small but measurable source of radiation.