https://users.stlcc.edu/mfuller/Tuneinir/area2.html

pXRF analysis: (320) barium = 571.56 ppm +/- 46.47, antimony = 75.34 ppm +/- 11.88, tin = 54.5 ppm +/- 10.43, cadmium = 26.77 ppm +/- 8.45, silver = 22.45 ppm +/- 5.86, zirconium = 46.85 ppm +/- 8.91, strontium = 327.48 +/- 7.42, rubidium = 18.17 ppm +/- 2.3, lead = 40.82 ppm +/- 7.23, arsenic = 21.16 ppm +/- 6.32, mercury = 7.59 ppm +/- 4.29, zinc = 78.07 ppm +/- 10.63, copper = 1598.86 ppm +/- 43.75, nickel = 32.69 ppm +/- 20.78, iron = 5762.63 +/- 127.64, and manganese = 387.71 ppm +/- 50.35.

Thin section analysis by Dr. David Bridges identified shattered quartz sand grains added as a component of the frit ware paste.