Potassium-Calcium Glass: New Data and Experiments*
W. B. Stern|Y. Gerber
The chemical composition of potassium–calcium ‘wood‐ash’ glass reflects the elemental pattern involved non‐volatile base materials in quartz sand, wood ash and possibly potash. essential ratio K 2 O/CaO varies between 0.2 0.8, depends on habitat geological substratum rather than tree species; ratios 1.0 3.0 wood‐ash are only possible when potash is added as a third material. Melting temperatures sensu stricto, termed K–Ca‐2, produced with two raw sand ash, 1250°C 1400°C, while those three‐component‐glasses, K–Ca‐3, 900°C 1250°C, according to amount Experimentally displays different hues, from colourless brown, olive‐green pink, ash. Elevated MnO concentrations 0.5 3 wt% may originate hence not necessarily an indicator colour‐inhibiting additives. Phosphate stemming discriminator potash–lime glass. Because contains minor amounts sodium, equal potassium sodium hybrid type, where besides also soda‐rich cullet have been applied for production.
Archaeometry