Thread: I Found It Over There

I live in florida and I once found a nice chunk of quarts down by a lake. I have no idea where it came from nor do I know where it is anymore. There was obviously no other stones like it around. As to paraphrase Morgan Freeman, Its a rock that has no earthly business being there.

Ok....you guys are getting way ahead of me lol. I have seen some formations with mybe one inch thick layers that could be seperated fairly easily, I just have to remember where I saw them. These I picked up only because they looked interesting. The green one is made up of paper thin layers, it almost looks like hair up close. All three take steel from a file on the lapped areas. Thank you guys for providing some good info. I'm still lapping, my arm is gettin tiered.

eKretz, when you check with the file, is this on a small lapped area or on a fractured face? I'm assuming you are talking about checking rocks in the field before bringing them home.

Originally Posted by bluesman7

eKretz, when you check with the file, is this on a small lapped area or on a fractured face? I'm assuming you are talking about checking rocks in the field before bringing them home.

I check on a small lapped area. If you check just on the rough stone you can get some idea if it will cut steel but it won't give you a very good indication of cutting speed or finish. Over time you'll get a better idea of what stones to look closer at. Sometimes the sparkle will indicate a stone that will cut steel and sometimes not. Sometimes a stone without any sparkles will work great. My Jnat for instance doesn't have any that I can see and it cuts like crazy.

Conchoidal fracture can be found in stone beside novaculite - flint, obsidian, quartzite and a couple others. The main thing is most of the rocks that fracture this way are very high in silica. Novaculite for instance is like 99.6+%, quartzite ranges from the low to high 90's percentile. Another good field check is to break off a chunk and check the grain size - finer stones will usually be finer grained on the fractured surface, but you'll need to get more familiar with seeing different stones to get an idea what that even looks like.

I don't like to check with a knife personally because they are usually not as hard as a razor - a stone that will cut a quality file will cut anything, where a stone that might cut a softer knife may not cut the file or a razor. If you have a knife of known hardness that is 60+ Rc then that is different though. Shaun knows his stuff so I'm sure he has it handled.

Originally Posted by Ranzor

Ok....you guys are getting way ahead of me lol. I have seen some formations with mybe one inch thick layers that could be seperated fairly easily, I just have to remember where I saw them. These I picked up only because they looked interesting. The green one is made up of paper thin layers, it almost looks like hair up close. All three take steel from a file on the lapped areas. Thank you guys for providing some good info. I'm still lapping, my arm is gettin tiered.

That is one of the issues with hard rock is that it is very hard to work with. Rock that separates into layer like you described is often slate or shale. One of the issues I have here is that the shale is too badly fractured to be able to work with most of it. The slate is a little easier but often has gas bubbles in it. However if you can find a good layer they both have the potential of great hones.

This is on an area already lapped on the DMT.

Wow that sucks about the notes.

Well I have to recant on the file. I realized I was testing with a cheap Cobalt file. Not so much luck with a Smith file. I will keep messing with these to see what they will do.

If I am uncertain I test with an old knife with a wide bevel.

Will do......if I ever get the damn thing lapped.

Originally Posted by Ranzor

Will do......if I ever get the damn thing lapped.

If it is Sioux Quartzite, it is a hard, hard rock! Good luck with it.