Asked in Geology
What igneous rocks looks like smooth glass?
There is a black rock known as obsidian that is extruded from volcanoes. Obsidian is hard and brittle and that is why it fractures with very sharp edges. Obsidian was used as arrowheads, obsidian carvings, and even obsidian blades in the stone ages. ...
Asked in Geology, Physics, Chemistry, Igneous Rock
What are the physical properties of obsidian?
Obsidian is a type of igneous rock that cools instantly after a volcano explosion. Obsidian forms when lava enters the water directly after the volcano erupts. The water instantly cools the lava leaving the mineral crystals no time grow. obsidian does not have any minerals and is often classed as a mineraliod. Obsidian can be brown, black, or black and white. Obsidian can often be found in the shape of arrow heads because it was used as a primitive arrow. obsidian is...