Conway granite Conway granite Conway granite is a typically pink mineral-rich igneous (or mesoperthitic) biotite granite. It is amphibole-free and of coarse particle size (with portions of the rock fine-grained or porphyritic). Conway granite has a relatively high concentration of thorium, at about 56 (±6) PPM; this amount is not enough to make the granite dangerously radioactive, but it is sufficient to make the rock a low-grade (almost certainly not economic, at least in the early years) source of thorium for a thorium fuel cycle. Geologist Edward Hitchcock named the granite in 1877 after the town of Conway, New Hampshire, which is
California Coastal Comm'n v. Granite Rock Co. largest in California, and the largest west of the Rocky Mountains. In 1980, Granite Rock submitted to the Forest Service a five-year plan to remove substantial amounts of limestone from a quarry on the south face of Pico Blanco within the National Forest boundary. The Forest Service prepared an Environmental Assessment of the plan and recommended some modifications, which Granite Rock implemented. When Graniterock obtained the permit in 1983, it began to excavate a open pit mine. The California Coastal Commission required Granite Rock to apply for a coastal development permit for any mining undertaken after the date of notification.