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
Granite Island (Michigan) Granite Island (Michigan) Granite Island is a island in Lake Superior located about northwest of Marquette in the Upper Peninsula of the U.S. state of Michigan. Built upon it is the Granite Island Lighthouse, also known as Granite Island Light Station, "one of the oldest surviving lighthouses on Lake Superior". It is part of Marquette Township, in Marquette County. The island is granite rock that rises nearly perpendicularly to above the surface of Lake Superior, surrounded by deep water. The Native Americans called the island "Na-Be-Quon". That apparently meant something like 'vessel'. They called a steam ship an "ishcoda nabequon".