Conchoidal Fracture
Here's a feature that I thought was really cool. It's a fracture in massive sandstone. Though the sandstone is made of individual sand grains (cemented together), and forms in layers, it responds as a uniform body when it fractures. This is the same sort of fracture that obsidian (or glass) makes--little "shells." I think this one is so cool. It looks like a giant inoceramid shell. Each rib is highlighted by desert varnish, making the ribs stand out. Note how the varnish forms on the upper surface of each rib, and the lower one is nearly free of varnish.
This feature is ~ 1 meter tall (more or less).
Conchoidal Fracture
Here's a feature that I thought was really cool. It's a fracture in massive sandstone. Though the sandstone is made of individual sand grains (cemented together), and forms in layers, it responds as a uniform body when it fractures. This is the same sort of fracture that obsidian (or glass) makes--little "shells." I think this one is so cool. It looks like a giant inoceramid shell. Each rib is highlighted by desert varnish, making the ribs stand out. Note how the varnish forms on the upper surface of each rib, and the lower one is nearly free of varnish.
This feature is ~ 1 meter tall (more or less).