Diamond now practical for use as a structural member in rocket engines?

Bill wrote:

> There is no advantage to diamond rocket nozzles. Like graphite, and
> coal, diamond burns at well under 1000 C. A rocket nozzle made of
> these materials, won't survive the liftoff.

The normal idea is to keep the nozzle away from oxygen. It
can't burn without an oxidiser. Surprisingly, graphite IS used
for rocket nozzles, and it works ok, but it's often plated
with a thin layer of metal to improve its properties further.
Probably you'd do the same with diamond.