(Click on the picture to return to Rock Type Lab key)
If you're considering purchase of a piece of property and there's lots of this stuff (fresh), you might want to reconsider. This rock resuts from explosive (silica-rich) magma eruptions. This sample comes from Oregon, which has seen a recent upsurge in tremors beneath volocanic McLoughlan Butte (~30 south of Crater Lake). Rhylite does not react with hydrochloric acid.
N. C. Heywood maintains this page, last updated 10NOV99.