A diamond-reinforced SiC ceramic composite material and shaped article. The addition of diamond to the microstructure greatly enhances properties such as hardness and Young's modulus. Such a composite material has considerable promise as an armor material. In particular, significant increases in ballistic performance can be achieved versus a non-diamond-containing composite, particularly versus the M993 threat. Reaction bonded silicon carbide (RBSC) ceramics with 7% diamond were shown to offer ballistic performance levels that matched the best commercial ceramics tested on the program.