Quartz hydration dating

The ion exchange phase in corrosion of nuclear waste glasses

“…This result is in excellent agreement with experimental findings [2], which reveal for water-altered quartz an Arrhenius temperature behaviour and linear dependency with C H for the effective diffusivity. Note that the concentration of protons at the glass surface is proportional to the concentration of protons (hydronium) in the water C H = jC Hsol , where j is a constant and C Hsol = 1(mol/L)10 ÀpH .…”

“…Studies of archaeological artefacts show that the principal processes in the natural corrosion of silicates are diffusion-controlled ion exchange reactions leading to selective leaching of alkalis and protons entering the silicate structure to produce a hydrated alkali-deficient layer and congruent dissolution with destruction of the silicate network and subsequent precipitation of hydrous silica-gel layers as secondary alteration products [1,2]. At ambient temperatures the ion exchange reactions persist for extended periods of time and govern alteration processes for thousands [1] and tens of thousands [2] of years.…”

“…At ambient temperatures the ion exchange reactions persist for extended periods of time and govern alteration processes for thousands [1] and tens of thousands [2] of years. The role of ion exchange in the corrosion behaviour of nuclear waste glasses is also considered to be important [3][4][5].…”

Fifty years of obsidian hydration dating in archaeology

“…The results of thermal expansion, density measurements, Vicker's hardness, chemical durability, electrical properties, Mössbauer and infrared spectra were presented by Ericson et al [15]. They found that obsidian is a glass of high chemical durability, comparable to Pyrex, and high hardness, comparable with silica glass.…”

“…Again, the results reported to date were problematic though in cases correct and calibration errors culminated the deficiency of the method to be considered reliable and precise [11,15,29,49,54,[58][59][60].…”