noun \əb-ˈsi-dē-ən\

: a dark natural glass that forms when lava cools

Full Definition of OBSIDIAN

:  a dark natural glass formed by the cooling of molten lava

Origin of OBSIDIAN

New Latin obsidianus, from Latin obsidianus lapis, false manuscript reading for obsianus lapis, literally, stone of Obsius, from Obsius, its supposed discoverer
First Known Use: 1796


noun    (Concise Encyclopedia)

Natural glass of volcanic origin that is formed by the rapid cooling of viscous lava. It has a glassy lustre and is slightly harder than window glass. It is typically jet black, but the presence of hematite (iron oxide) produces red and brown varieties, and tiny gas bubbles may create a golden sheen. It is sometimes used as a semiprecious stone. Obsidian was used by American Indians and others for weapons, implements, tools, and ornaments, and by the ancient Aztecs and Greeks for mirrors.


Next Word in the Dictionary: obsidianite
Previous Word in the Dictionary: obsessus
All Words Near: obsidian

Seen & Heard

What made you want to look up obsidian? Please tell us where you read or heard it (including the quote, if possible).