the blade plays a very important role in many heathen/pagan/neo-pagan practices.... A hawkbill blade called a boline is sometimes used for harvesting herbs used in ritual practices.
Several years ago, a local pawn shop called me up saying he had one of those strange knives with two handles that I like and occationally buy from him. This one was all copper. "Copper handles, right? That'd be unusual, but not unheard of."
"No, it's all copper, the blade and all."
A knife with a copper blade! That could pre-date the iron age. We're talking museum artifact here. And if the balisong design could be shown to pre-date the iron age, that would be huge! Of course, I dropped everything and went immediately.
Well, it was clearly a modern knife with some strange symbols carved on the handles. I wasn't sure what to make of it. It was a nicely made knife, sure, buy why copper? I figured it must be some made-in-China cheapie. And the guy was claiming it was a custom knife and wanted a bit of money for it -- not much, but more than I'd care to pay for a Chinese cheapie. So, I took some notes and went home to see what I could find.
What I discovered was that certain pagan/witchcraft/satanic rituals (I don't know exactly which flavor) require herbs cut with an all-copper knife. Apparently, it's usually a fixed-blade knife that's used. Apparently, the rituals in question don't specify a fixed or folding knife, though, and someone had had one made in the balisong style. The symbols on the knife were related to those rituals. Anyway, I declined to purchase what I labeled, "The Satanic Balisong."
Some months later, I received a telephone call from a person seeking balisong lessons. This person was very excited about having purchased this copper balisong. I asked if this person was aware of what that knife was for. She was. Well, I wasn't to excited about spending any time with this person, so I basically blew her off.
Anyway, there's an interesting bit of knife trivia for you if you see a copper knife.