Board Thread:Suggestions forum/@comment-26149161-20160124141939/@comment-25754873-20160124173344

Gen. Grievous1138 wrote: It should be dwarven-uruk mineable only. But Orthanc was not made of black Gondor brick, it was made of pure obsidian.

Gen. Grievous1138 (admin) comlink 16:07, January 24, 2016 (UTC) It was made of black unbreakable stone which was made by the Numenoreans