Obsidian

Obsidian

Obsidian is a naturally occurring volcanic glass formed when lava extruded from a volcano cools rapidly with minimal crystal growth. It is an igneous rock. Produced from felsic lava, obsidian is rich in the lighter elements such as silicon, oxygen, aluminium, sodium, and potassium. It is commonly found within the margins of rhyolitic lava flows known as obsidian flows. These flows have a high content of silica, giving them a high viscosity. The high viscosity inhibits the diffusion of atoms through the lava, which inhibits the first step (nucleation) in the formation of mineral crystals. Together with rapid cooling, this results in a natural glass forming from the lava.

Obsidian (character)

Obsidian is a superhero published by DC Comics. He first appeared in All-Star Squadron #25, and was created by Roy Thomas and Jerry Ordway. He is the son of Alan Scott and Rose Canton and the twin brother of Jade. According to an Infinity, Inc. letter page, Obsidian was named "Todd" after a friend of Thomas.

obsidian

Noun

1. A type of naturally occurring black glass produced by volcanoes.
2. A slightly bluish black, the color of obsidian glass.

Adjective

1. Black.