Bought some uranium glazed pottery (Fiestaware) from eBay for about 10 GBP. Measured it at my work with a professional pan-cake survey meter, the Saphymo Minitrace S5. The minitrace measures ~70uSh/h. Note: not energy compensated and calibrated on a Cs-137 source.
My personal GMC-320 Plus measured around ~13uSv/h, after stabilizing around 2000CPM after a few minutes. Not bad, given the difference in detection area (pancake GM with a foil that detects alpha, beta & gamma versus a tube GM which can only detect some beta and mostly gamma) and price difference. :-)