Beach Rocks
Rhyolite
![](images/Rhyolite/RhyCobs.jpg)
![](images/Rhyolite/il_570xN.728653353_fex0.jpg)
![](images/Rhyolite/MtHoughtonGeo.jpg)
![](images/Rhyolite/droppedImage.jpg)
![](images/Rhyolite/FlBandedRhy.jpg)
Rhyolite is high silica lava, quite common in the conglomerates of the Keweenaw and also in some small bodies along and near the Keweenaw Fault, like Mount Houghton. Rhyolite is a hard rock and makes smooth beach stones, usually reddish in color.
Flow-banded rhyolite
Geologic map of Mount Houghton, Keweenaw. This is the highest point in the peninsula. The red area is a volcanic dome.
![](images/Rhyolite/colorWeb.jpg)