reply to post by SixX18
Hate to jump on the bandwagon, but from what I can see it's slag glass, or man-made glass.
1. I collect quartz as a hobby - First of all, just by looking at the fracture in the pictures, it doesn't have the appearance of any quartz crystals
I've seen (and yes, I have seen specimens up close; envy some of the dealers at the rock & mineral shows with their big crystals).
2. If it's got bubbles in it, and it is as clear as the photos show, then it's not quartz. One of the first things I was taught is that while quartz
can have air/water bubbles in it, if you find a very clear, large sphere and it contains a lot of bubbles, then chances are it's glass.
3. I've found chunks of slag glass hundreds of feet away from the nearest railroad, in areas that you'd think you were the first person to visit.
One of the things I've always liked about nature is that if you leave it alone long enough, then it will eventually reclaim the land. In this case,
my suspicion would be that there was a building or area nearby that produced the slag as a by-product (maybe ore refinement). In this case, the ore
would have been exported or shipped out, and the glass was dumped near the creek in piles. Over time, the piles were moved or spread-about.
The reason I say this? My bet is that the cave was actually part of a coal/steel refinement plant at one point - Sulfur & slag glass are both a
byproduct from the refinement process.
4. Remember, your friend only found something close to the surface; I'd bet that if you dug a little deeper in the surrounding area, you would find
more bits & pieces.
For example, I have a park near me that used to have a really old subdivision in it - On the surface, there isn't much to see. In order to find the
"dumps" that the people left at the time, you'd need to get down next to the river bed to find the treasure. I've found broken pottery, old
marbles, toys, and someday I'd love to find an arrowhead. Back then, the mentality was dig a hole, bury the broken items/disused items, and cover it
up. The fun part was that I could actually dig through the layers of stuff, track back through the years.
In short: Slag Glass is my vote
PS: Not that I'm saying he could make a profit, but down in some of the southern states they do sell this for a good sum of money - One the size of a
bowling ball would fetch a considerable sum, I'll wager. They also attach a fancy name onto it to trick those that buy it into thinking it's
something more than glass - Didn't fool me, but it sure fooled the poor souls next to me.