The size of an average sized head
the size of the average human head
Obsidian is natural glass.
Obsidian is part of the Granite family of igneous rocks.
An obsidian rock is an extrusive igneous rock that forms when a volcano erupts and has no time to crystallize, so it has a glassy texture. Obsidian rocks are generally black in color.
because an obsidian rock has low silica
Obsidian is black glass formed by volcanoes.
Some incredibly sharp surgical instruments are made of obsidian.
obsidian rocks are red and black also sometimes orange
Obsidian is formed from very rapidly cooling lava.
No. Pumice and obsidian are rocks composed mostly of glass.
Obsidian and coal are both rocks and they are formed by lava
Obsidian is a fairly common and has little collector value. The only Obsidian that has a bit more value is Rainbow Obsidian. Which is still fairly common.
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.
Obsidian rocks are found on the west coast near the pacific ocean by volcanoes because it is cooled lava called volcanic glass
Obsidian and Basalt are both Igneous rocks. They are made from hardened lava from volcanoes.