"Radioactive red" was a popular uranium glaze in the
1930s and 1940s. The small plate is the well-known
Fiesta made by HLC. The other two items were
made by less distinguished California potteries, but
are nonetheless plenty radioactive.
The unmistakable, fiery brilliance of "radioactive red" glaze makes such radioactive pottery stand out from miles away at antique malls and flea markets. Best known is Homer Laughlin's popular art-deco pattern, Fiesta. But red glaze containing up to 15% uranium by weight was widespread on the wares from other "California" potteries also.
This glaze is a prolific source of beta radiation in particular. Count rates in excess of 35 kCPM on a pancake Geiger tube are typical. Is it safe to eat off this pottery? In general, yes. But acidic foods tend to leach uranium out and increase exposure. Probably of greater concern is the lead in the glaze, which is not limited to red only. (The FDA now prohibits manufacture of such tableware.) Enjoying enormous popularity in its heyday, Fiesta ware and other radioactive ceramics will continue to be abundant at antique malls, garage sales, and flea markets. Thus, they are an excellent way to begin a radioactive material collection or set the dinner table for your mother-in-law's visit.