Hi Roger,

Thanks for the link. Most of the books Don and I have explored to identify rocks are not all that useful. I've got chert in a whole variety colors and textures that only a true geologist would know what these were. Imagine a small piece that is layered and is black, orange, white and brown. When you ask yourself, "does this look like anything you've seen in a book?" the answer is an absolute "no." Yet the primary chert one finds in Parkfield is a light shade of green and it has a wonderful soft texture.

Everything we find up here in my area is volcanic. From the bombs that look like oversized potatoes to flow layering. All quite interesting. But for the novice, I need a lot of help and that web site may just advance my knowledge.

Thanks for posting the link.

Petra