Obsidian is formed as extruded lava with a high silicon content that cools quickly. So the environment would be a volcano.
obsidian
The glassy texture of obsidian is the best evidence that it formed in an extrusive environment. Obsidian is rapidly cooled lava with no time for crystal growth, resulting in a smooth, glass-like texture.
Obsidian has a glassy texture because it cools very quickly when erupted onto the Earth's surface. This rapid cooling prevents crystal formation, resulting in a smooth, glass-like appearance. The high silica content of obsidian also contributes to its glassy nature.
Obsidian is an extrusive rock formed from rapidly cooling lava with a glassy appearance that can easily be mistaken for actual glass due to its smooth texture and lack of crystal structure.
Obsidian is an extrusive igneous rock with a mafic composition and a glassy texture. This rock forms from the rapid cooling of lava with high silica content, preventing the growth of mineral crystals and resulting in its glassy appearance.
Obsidian.
obsidian
Obsidian is an extrusive rock that cooled very rapidly without forming crystals. As a result, obsidian has a smooth, shiny texture of a thick piece of glass.
The glassy texture of obsidian is the best evidence that it formed in an extrusive environment. Obsidian is rapidly cooled lava with no time for crystal growth, resulting in a smooth, glass-like texture.
Obsidian is an glassy, extrusive, igneous rock that is found in areas that have experienced rhyolitic eruptions. Obsidian is formed when the rhyolitic lava comes into contact with water. This quick-cooling results in the glassy texture of obsidian.
They cool to quickly for crystals to form.
Obsidian has a glassy texture because it cools very quickly when erupted onto the Earth's surface. This rapid cooling prevents crystal formation, resulting in a smooth, glass-like appearance. The high silica content of obsidian also contributes to its glassy nature.
Obsidian is an extrusive rock formed from rapidly cooling lava with a glassy appearance that can easily be mistaken for actual glass due to its smooth texture and lack of crystal structure.
Andesite is considered an extrusive igneous rock.
Obsidian is an extrusive igneous rock with a mafic composition and a glassy texture. This rock forms from the rapid cooling of lava with high silica content, preventing the growth of mineral crystals and resulting in its glassy appearance.
Obsidian is an extrusive igneous rock that forms when lava cools quickly and solidifies into a glass-like material without crystal formation. It is typically black in color and has a smooth, glassy texture due to its rapid cooling process.
Obsidian: Its texture is glassy. Obsidian is extrusive or volcanic, because the instantaneous cooling that produces such rocks is a surface phenomenon. Obsidian is amorphous, so, unlike true rocks, it is not composed of minerals.