Abstract: An apparatus of forming non-agglomerated nanostructured ceramic (n-ceramic) powders from metalorganic precursors combines rapid thermal decomposition of a precursor/carrier gas stream in a hot tubular reactor with rapid condensation of the product particles on a cold substrate under a reduced inert gas pressure of 1-50 mbar. A wide variety of metalorganic precursors is available. The apparatus is particularly suitable for formation of n-SiC.sub.x N.sub.y powders from hexamethyl-disilizane or the formation of n-ZrO.sub.x C.sub.y powders from zirconium tertiary butoxide. The n-SiC.sub.x N.sub.y compounds can be further reacted to form SiC or Si.sub.3 N.sub.4 whiskers, individually or in random-weave form, by heating in a hydrogen or ammonia atmosphere. The non-agglomerated n-ceramic powders form uniformly dense powder compacts by cold pressing which can be sintered to theoretical density at temperatures as low as 0.5 Tm.