A sacrificial victim whose heart was about to be cut out with an obsidian knife?
From the guardian.co.uk
In addition, obsidian, flint, and other minerals were mined, worked, and traded.
From the en.wikipedia.org
In New Britain, settlements are found inland as well, near the obsidian sources.
From the en.wikipedia.org
I pat the hood of an obsidian-black 2011 Chevy Volt, on loan to me for the day.
From the washingtonpost.com
Obsidian is a form of natural glass which forms when volcanic lava cools quickly.
From the independent.co.uk
His face was covered with what may have been a funeral mask with obsidian eyes.
From the guardian.co.uk
Obsidian demanded she reveal the source of her information to prove its veracity.
From the infowars.com
The stock of obsidian is controlled and traded with neighboring hunting groups.
From the en.wikipedia.org
The Climate Changer will be available fall 2009 in obsidian black or forest green.
From the sltrib.com
More examples
Acid or granitic glass formed by the rapid cooling of lava without crystallization; usually dark, but transparent in thin pieces
Obsidian is a naturally occurring volcanic glass formed as an extrusive igneous rock. It is produced when felsic lava extruded from a volcano cools rapidly without crystal growth. ...
Obsidian is a computer game, written for the Amstrad CPC. It was written by Tony Warriner and published by Artic Computing. The game was released in 1986 to strong reviews.
Obsidian is a fictional superhero published by DC Comics. He first appeared in All-Star Squadron #25 (September 1983), and was created by Roy Thomas and Jerry Ordway.
Obsidian is the name given to several fictional characters in the various Transformers universes.
Obsidian was a 1996 computer game created by Rocket Science Games for Mac OS and Windows platforms.
A type of black glass produced by volcanos; black
Is a natural glass that is formed from lava that cooled too quickly to crystallize.
Very hard volcanic glass used for tools. It can be dated by measurement of thickness of its hydration layer on surface