* It's a misspelling: Perhaps you meant "obsidian," which is a dark, volcanic glass.
* It's a niche term: It might be a technical term in a specific field, like geology or a particular industry. If you can provide more context, I might be able to help.
* It's a made-up word: Maybe you're thinking of a fictional term or a personal creation.
Please provide more information about where you encountered the word "osibian" so I can assist you better.