Insurance? (USA)

Those of you with geodesic dome homes; where do you get your homeowner's insurance?

It seems that for some reason all the "normal" companies have no idea how to insure a dome and won't even talk to me about a policy.

The reason they give is that they only sell policies for "replacement cost" which they can't calculate because there is no entry for "dome" in their drop down menu.

On the other hand, my local township has no problem estimating my dome's value for the purpose of assessing property taxes, but these insurance companies with oceans of data can't do it?