Obsidian stones

The way back to the entrance of the national park, passes through a flat desert landscape with lots of stones and pebbles strewn around. Our guide told us that one could find obsidian stones spread in the desert sand. Obsidian is a volcanic glass created as an extrusive igneous rock. Basically, the magma cools into a glass/rock form once it is outside of the crust to form obsidian.
We stopped for a while to search for obsidian rocks. They were spread all over and were very easy to find. These are used as black glass in jewelery. After stopping there for a while, we continued further out of the national park back towards San Pedro de Atacama.もっと詳しく