This is a Earth Cache. There is no physical contaner to find but rather a geological lesson to be taught.
There is a admission price to enter the museum of apx. 10 doallars per adult and 7 doallars per child.
Obsidian: Obsidian is formed by rapidly cooling molten rock or lava. Some examples of how it could form are: lava flowing into a body of water, or lava splashing against something and being reflected back into the air. Most obsidian has been formed withing the past couple million years. Most obsidian that was formed before that has deteriated over time. It usally has sharp edges (but not always!). That is due to the lack of crystalline which causes the fracture surfaces to be really sharp. It has a distinctive smooth, glassy look. It is dark in color most of the time, but can be nearly transparent on rare occasions. Iron and magnesium can make it green in color.
Clay: A fine-grained natraul soil. It develops "plasticity" when wet. That is due to a molecular coating of water surrounding it. It is a very common substance. You can identify it due to its lighter color. It is also thick, but flexible. Lots of people even today use clay commonly. The Hohokam built houses, and tools out of it. Clay is hard when it has been fired or cooked.
Crystalline: Having the form of a crystal
To log this cache as a find, please email or message me the anwers to the questions below:
1. At the posted coordinates, how do you know the houses were made of clay based on the definition above?
2. Was there any obvious use of obsidian in what is left of the clay structures?
3. Give me your best estimate of how many clay structures you can see from standing at the posted coordinates.
Make sure to go to this cache on the website and discover the virtual TB here! The tracking code is on its page.
Sites used:
Clay - Wikipedia
Obsidian Cliff - Yellowstone National Park (U.S. National Park Service) (nps.gov)