Sure can, this rock has it's own special US Customs description as the rock was submitted to them, analyzed and classified by the US Government.
This is not considered coral, as ALL other rock is that is in the Industry. So very easy to ship without any customs, or US Fish and Wildlife permit.
Also I have shipped aquacultured rock to Canada, VIA a US airport many times.
Nobody has ever encountered any problems at the border, just declare it, pay some tax as the Canadians have there own designation for cultured rock. It is taxed and recognized as 'limestone' by them. Ask here in RC there are a few of your countrymen who have done it.
Richard TBS