Dating purple glass norway dating agencie
While this produces colorless glass, that glass will turn a light purple or amethyst color when it is exposed to sunlight.
Dating of solarized glass by archaeologists has relied on information from a variety of sources, including books produced by bottle collectors.
Iron in sand gives the glass a range of colors from light green to dark amber, depending on the amount of iron in the sand.
To overcome this problem, some factories that used iron-bearing sands added manganese to their batch as a decolorizer.
One of the better discussions on this is from The Parks Canada Glass Glossary by Jones & Sullivan (1989), and is quoted below:"Because colour is a universal attribute of glass and is convenient for mending and establishing minimal vessel counts, it has been latched onto by some archaeologists as a classification device.
It is a much appreciated page of information you can include when mailing EAPG to customers.Low iron means more control over the ultimate color (Hunter 1950; Tooley 1953).Glass which is composed of pure silica (99.9% ) would be colorless glass.The silica (silica dioxide) typically makes up 60-80 % of the glass composition and is primarily derived from sand.The purer the sand (i.e., the higher the silica concentration and less iron) the better, as it is the other impurities - desired or undesired - that give glass its color.