Bleah. Nothing similar to this under "souseiseki" or "翠星石" on images.google.com, images.google.co.jp, images.yahoo.co.jp, pixiv, or even *shudder* deviantart. My OCD has seriously kicked in.
I did catch reference to 4chan on nekobooru, but obviously that had dried up already. If that's where they all came from, it would explain why the backtrail is missing. I haven't finished checking the other image boards, but their tagging isn't anywhere near as thorough as it is here.