quartz block

A block of nearly pure quartz near the shore of Star Lake, Mt Madison NH. Blocks like this (but mostly smaller) occur occassionally throughout the northern Presidential Range - you see them on the summit cone of Mt Washington in particular, where they're easily mistaken for snowfields. Breadloaf-sized quartz pieces are frequently used as the top stone in cairns for marking trails in the Presis. I think I can see this block in satellite images. This image is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 3.0 License.