Volcanic rock (dacite) as art
![Dacite](https://d9-wret.s3.us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/full_width/public/thumbnails/image/13%20dacite_0.jpg?itok=crF7zOZU)
Detailed Description
Volcanic rock (dacite) as art. The Portland Art Museum hosted a gallery installation about the art and science of the Mt. St. Helens, complete with a reading room and USGS equipment and publications.
Sources/Usage
Public Domain.