Hand ax?

[Rockcrk]

I agree. Would have made a lot of arrowheads or knives. That's why it's so unusual to see a big tool like this made from a silicate.

[clovisoid]

Great looking material.

The big spall could have been a lot of things, but my guess is was planned to be a core. In the hands of a great knapper that piece would have made a lot of little agate points if traded down river. Along the way it could have been used as a heavy cutting tool, etc.

[Garguy]

The large item posted is a large spall struck and heat treated. The fire pop might have prevented the maker from continuing the reduction process. Also it looks like he took test fakes around the edge so it jay gave been discarded because it didn't work well or just stored to be used later.

[redrocks]

Very nice!

[Rockcrk]

That's the other side.

[Rockcrk]

Yeah....a miracle for sure.

[Fla.Hillbilly]

And how it didnt shatter when it popped is another qwandry

[Talkingpoints]

Thats real nice!

[Rockcrk]

It does look like a fire pop also but grabbing it on the narrow end the thumb is in a perfect spot to fit in that hole. I have a couple pieces that are fire popped but arrowheads. I do know opal had a lot more water in it than agate per se but my favorite point is a Carnelian agate fire popped Columbia plateau Arrowhead

[Ron Kelley]

It's a good sized spall. What you're calling a thumb-hole looks like a fire pop. There is water within the rock and when it's subjected to fire it will pop out cavities like that.

[Rockcrk]

Yeah. Definitely used for butchering. I like the thumb hole so their hands didn't slide off when bloody.

[SurfaceHunter]

Could be most of us can them choppers same thing though

[Rockcrk]

This was found on the Clearwater River. It is a Big piece of high quality Idaho common opal. I believe it to be a hand ax. I've seen alot of semi-precious gem stone artifacts come out of my area but nothing of this size. Tools of this size were usually saved for the more abundant basalt, granite, andesite, and quartz.