Someone found it centuries ago.
Neither, obsidian mirrors were first discovered in Anatolia (modern-day Turkey).
Obsidian was known to primitive peoples who fashioned this material into points for weapons and into edges for tools. In that light, no one "discovered" this amazing material we sometimes call volcanic glass. It was "discovered" well in excess of ten thousand years ago. Its use predates any writing by many ages. Links can be found below to related posts and questions.
No. Obsidian is brittle.
One type of obsidian is snowflake obsidian, which is black with white mineral inclusions that resemble snowflakes.
yes obsidian is a crystal.
Obsidian is, itself, a mineral.
Obsidian is a natural glass.
Obsidian is an igneous rock.
Other names for obsidian is Apache tears, volcanic glass, and Black obsidian.
Snowflake Obsidian
how is obsidian dependent on minerals
Obsidian is not magnetic.