What fushigi is in Japanese

A lot of people have been getting and talking about the Fushigi ball, so I want to explain what the Japanese word is.

First of all, the kanji looks like this: 不思議 (不 = fu, 思 = shi, 議 = gi), and it usually means "mystery", though some sources add "miracle", "strange", and "curiosity".

When I tell Fushigi ball fans that it's actually a Japanese word, they're surprised because they think it's some random word for that product. I've seen the ball, but I haven't tried it out, and don't really intend to. But apparently it makes some people happy.