A model for the shear modulus (modulus of rigidity), G, is now available (download calculator, 200 kB). It was developed by means of statistical analysis. Some interesting properties of the model are given here.

Number of data the model is based on = 627 (see source data references, 65 kB)
Degree of freedom = 603
R² = 0.9534
R²(adjusted) = 0.9516
R²(predicted) = 0.9490
Standard error = 1.0426
Mean of response (Shear Modulus in GPa) = 29.4283
Main glass composition validity limits of the shear modulus model in mol%: SiO2 45-86%, Na2O 0-42%, CaO 0-27%, Al2O3 0-25%, MgO 0-27%, K2O 0-25%, B2O3 0-29%, BaO 0-26%, SrO 0-25%, Li2O 0-40%, PbO 0-50%, ZnO 0-18%, TiO2 0-25%, ZrO2 0-9%, Fe2O3 0-5%, F 0-9%, As2O3 0-0.6%, Sb2O3 0-0.5%, SO3 0-0.4%, (numerous additional model validity limits apply, considering glass component combinations).

The following spider-graph shows the influences of selected glass component additions on the shear modulus of a specific base glass, while keeping the weight ratios of all remaining components constant. The spider-graph will be different for other base glass compositions.

Influences of selected glass component additions on the shear modulus of a specific base glass (click image to enlarge)

For the shear modulus model development, 32 outliers had to be excluded. These are possibly caused by inaccurate data reported by the authors in the original literature or by copying the original data wrongly into the SciGlass 6.7 database. A list of the 32 possibly erroneous shear modulus data is provided here (23 kB).