Are there any materials with a higher dielectric breakdown strength than diamond?

Diamond is quoted as having a dielectric breakdown strength of about 2 Gv/m on wikipedia:
https://en.wikipedia.org/wiki/Dielectric_strength

This 2 Gigavolts/meter value being the electric field strength at which diamond stops being an insulator and starts conducting current.

Are there any materials with a higher breakdown strength than 2 Gigavolts / meter? (2 Gv/m)