Creek find

KF5 · Feb 9, 2016

I don't know anything about rocks but my son really wants to know something about this so he can look it up & learn about it (ie why the outside looks so different & what the mineral is that's visible on the end broken off). The pics are the same rock, just looks different when light hits it.

DDancer · Feb 10, 2016

Almost looks opalized. A hardness test would help as well as a streak test. Most likely the material formed in a vug of some very soft material and thats what gives it its shape. The interior is somewhat crystalline towards the core and it may have formed much like an agate however its not agate. Interesting find.

hvacker · Feb 12, 2016

DD, do you think that might be amethyst in a misshaped geode?

DDancer · Feb 13, 2016

hvacker, Its possible. Looking at it in that frame of mind its more probable than my own initial thought as I keyed on the coloration around the edges... kinda foolish of me as opal does not lend to crystallization like that :tongue3:

. There is no real layering that I can decern however the larger part if broken might have it. Pretty massive formation of crystals so maybe its just a compacted vug.

Eu_citzen · Feb 15, 2016

Looks like quartz to me.

Backcountry · Feb 16, 2016

I was also thinking along the lines of an amethyst geode. But due to the strange shape, maybe more like a nodule as opposed to geode. It's pretty cool in any case. While the core is most interesting to look at, the surface is pretty neat too, almost looks like it's been carved. Not to get too woo-woo, but it could have some interesting metaphysical properties if you were inclined to that kinda thing.

KF5 · Feb 17, 2016

We didn't even notice the core until we got home & unloaded our finds. The reasons we kept it were the 1) the interesting shape nything we ha& 2) the carved look the surface had. Definitely different than anything we have found before.

DDancer · Feb 17, 2016

Its definitely a neat piece. Wonder if the exterior could be treated to clean it up. Might show some interesting color. Cutting will probably bust it up but careful polishing on one side or a small area might be feasible.