Zirconium tungstate (Zr(WO4)2) is a metal oxide with unusual properties. The phase formed at ambient pressure by reaction of ZrO2 and WO3 is a metastable cubic phase, which has negative thermal expansion characteristics, namely it shrinks over a wide range of temperatures when heated. In contrast to most other ceramics exhibiting negative CTE (coefficient of thermal expansion), the CTE of ZrW2O8 is isotropic and has a large negative magnitude (average CTE of -7.2x10?6K?1) over a wide range of temperature (-273°C to 777°C). A number of other phases are formed at high pressures.