A Determination of thec44Elastic Constant for Beta-Quartz

A careful determination of the elastic constant $c_{44}$ of beta-quartz has been made using the method of Atanasoff and Hart. The results obtained, $c_{44}=35.75\mathrm{}\times {10}^{10}$ dynes/${\mathrm{cm}}^2$, differs by a factor of nearly two from the only other published value. A study of the behavior of this constant in the range 0° to 650°C, the consistency in the value obtained from different cuts from different crystals and other facts seem to justify the value of the constant here determined.