Glaze, lead

Two types of glazes have been in use on earthenware since hundreds of years. They are lead and tin glazes. Lead glaze is transparent, and tin glaze is white and opaque. 

Easy lead leaching from glazes can be prevented by the use of fritted glazes. Here, the glaze composition is first melted and powdered. This powder is then used for glazing. 

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During the 1960s, Americans lived in a lead-drenched society. They fueled their cars with leaded, antiknock gasoline. They ate food and their babies drank milk from lead-soldered cans. They stored drinking water in lead-lined tanks and transported it through lead or lead-soldered pipes. They squeezed toothpaste from lead-lined tubes and poured wine from bottles sealed with lead-covered corks. They picked fruit sprayed with lead arsenate pesticide and served it on lead-glazed dishes in houses painted and puttied with lead-based compounds. 

Roberge RJ, Martin TG, Dean BS, et al. 1994. Ceramic lead glaze ingestions in nursing home residents with dementia. Am J Emerg Med 12 77-81. 

Roque J, Molera J, Sciau P, Pantos E, Vendrell-Saz M (2006) Copper and silver nanocrystals in lustre lead glazes development and optical properties. J European Ceramic Society 26 3813-3824. 

Colored glazes are made with the addition of nearly pure oxides of manganese, copper, iron, chromium, cobalt, et cetera ) opaque glasses, ot enamels, by the addition of oxide of tin, or phosphate of lime for which see Porcelain True and Earthenware, Some of the ordinary lead glazes for soft porcelain are given below —... 

The higher degree of transparency, together with the softer nsture of the lead glaze, is one of the distinguishing features of soft from real porcelain.. The manner in which the pasta was formed into. vessels ia similar to that in the other branches of the manufacture... 

Glazes for pottery are described much as in the earlier divisions of the work, but here lead glazes are described. 

Majolica is an earthenware pottery characterized by a creamy light-buff-colored paste and an opaque white tin-lead glaze coating the entire outer surface of the vessel. However, the most outstanding feature of the majolica pottery perhaps lies in its decoration, being the subject of numerous studies by art historians. Majolica decorations are produced from metallic oxides that always are applied on top of the tin glaze. 

A different problem related to Sevillian pottery is that several specimens are not considered to be true majolica, but rather a lead-glazed pottery. A few of these samples have been considered in the present study, five of which are clearly of a Sevillian origin (2 honey samples, 2 green samples and 1 blue sample). Moreover, as discussed above, XRF indicate that five of the 7 ungrouped samples could be Sevillan products, but contain significantly lower concentrations of CaO and Sr. All... 

Schwedt, A Buxeda i Garrigos, J. Madrid Fernandez, M. In Study of Technological Differences in Tin Lead Glazes, paper presented at EMAC 05, Proceedings of the 8th European Meeting on Ancient Ceramics Lyon, 260>-29fl> Odober, 2005 Lyon. 

LA-TOF-ICP-MS may be a useful tool for distinguishing different sources of lead found in low-lead, alkaline-based and lead-based glazes from Mesopotamia. Even with the limitations of the present study, lead-isotope ratios determined by TOF-ICP-MS indicate that multiple ore sources were utilized by makers of Islamic lead-glazed pottery. With the further refinements of Dudgeon et al. (this volume), LA-TOF-ICP-MS promises to be a rapid, cost-effective approach to lead-isotope ratio analysis of glazed pottery. 

Later Islamic Post-Ninth century A.D. The first lead-glazed pottery, sgraffito is produced outside of southern Mesopotamia (INAA Group 3). Alkaline-based and low-lead, alkaline-based glazed pottery continues to be produced (INAA Group 1). INAA Group 2 ceramics continue to be produced. 

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