Alpha silicon carbide (α-SiC) is the most commonly encountered
polymorph; it is formed at temperatures greater than 1700 °C
and has a hexagonal crystal structure (similar to Wurtzite). The
beta modification (β-SiC), with a zinc blende crystal structure
(similar to diamond), is formed at temperatures below 1700 °C.
Until recently, the beta form has had relatively few commercial
uses, although there is now increasing interest in its use as a
support for heterogeneous catalysts, owing to its higher surface
area compared to the alpha form.