It hardly conducts any electricity at all, so we can say it’s an electrical insulator. Inside the plastic ... graphite is an example of a non-metal which is a good electrical conductor.

Experiment has now proved the existence of the predicted three-dimensional 'topological insulator' in the semiconducting alloy Bi 1−x Sb x. One of the triumphs of quantum mechanics in the ...

It is difficult to reconcile these observations with a transcriptional insulator model. For example, a reasonable prediction from the decoy model is that two insulators would be better than one.