Author name: Russell J. Hemley

The synthesis of large single-crystal diamonds by chemical vapor deposi- tion (CVD) at high growth rate has opened a new era for applications of the material. Large and thick single crystals can now be produced at very high growth rates, and the mechanical properties, chemistry, and optical and electronic properties of the material can be tuned over a wide range. The single crystals can have extremely high fracture toughness and exceptionally high hardness following high-pressure/high-temperature annealing. CVD single-crystal diamonds will make possible a new generation of high-pressure–temperature experimentation to study Earth and planetary materials and should enable a variety of other new scientific and technological applications.