Question on rock ? Options

[burrell]

Found this last trip. It is hard and wasn't able to scratch with a small pic tool. The only thing i've done is wash it up with dawn. If this picture comes thru i have 2 more that will follow.

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[burrell]

#2

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[burrell]

#3

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[Coalbunny]

The host rock, the white stuff, is quartz. Very hard rock. The rust is limonite, or at least one or more of the multitude of oxides (tin, iron, manganese, etc.). There is one item there I cannot readily identify, but I'm thinking it may be a type of sulphide, like iron pyrite, or something similar. There isn't much if any visible staining of oxides like limonite around it, so I'm uncertain. It would have been best if you had pics before and after the cleaning.

[burrell]

Yea the grayish looking stuff is what i'm wondering about. There wasn't much that cleaned off of the quartz rock mostly mud and dirt i got on it between creek and home. It is hard(grayish part) and does seem to have some stainig from a tea color to a kind of pink color. It almost looks like its in squares. A small peice did fall off about -1/8" and squarish. The last picture is about the best of the 3. The only noticable staining is dark stain below it. The rock does show more heavy staining inside of it which might be the same stuff visible lower on the rock which appears to be a compressed red gritish mud. Would iron pyrite be that hard?

[Coalbunny]

Iron pyrite is not grey. From what you've said so far I'd say it sounds like possibly arsenopyrite. Who knows. I've also seen molybdenite in similar conditions as well.

So when you scratch the grey stuff, tell me what happens. How does it scratch? With what tool? How does it feel? How does it glisten? Stuff like that.

[burrell]

Tried to scratch with a cheap dental tool (pic). The best i can tell with a magnafying glass it didn't scratch. It is shiny and reflects light. Smooth to the feel but is ruff as pictured. Fractures in it seem to part of the natural fractures in the quartz rock it self. I looked at arsenic in a Chris Pellant rock min book and some does sound like what i have but the picture doesn't match up and this appears to be cubical instead of granduler. That could also be just the way the rock was fracturing. Also on the other end of the rock same edge it has some trigonal/hexagonal ( had to look that up)shapes clearer and the one i can get to is 3/8" wide per caliper. This is sandwiched into the quart and i hadn't noticed due to my tunnel vision on the grey/silver looking part.

[burrell]

Any suggestions on who and how large or small of a sample that i could send to someone that could say what the silverish part is? I'm glad i didn't start braking the rock up because i would have totally missed the crstals in the other side. I will try to post pics of crstals later on. To my untrained eyes i see several different materials in it. Camers not the best in LA. (lower Alabama)- FL panhandle

[DavidS]

#2

If that silvery metallic mass is not scratched by a sharp steel point. Then my best guess is the mineral "ARSENOPYRITE". Do not confuse this mineral type with "ARSENIC" or "PYRITE", for they are different minerals. Search the web for information, and pictures of this mineral. And I recommend when looking for pictures of any mineral, that you compare more than one photo. MOST minerals can have various forms, colors, and purity. But yes from what I see in your picture, It looks like Arsenopyrite in a massive form with "some" crystal structure.

[DavidS]

Any suggestions on who and how large or small of a sample that i could send to someone that could say what the silverish part is? I'm glad i didn't start braking the rock up because i would have totally missed the crstals in the other side. I will try to post pics of crstals later on. To my untrained eyes i see several different materials in it. Camers not the best in LA. (lower Alabama)- FL panhandle

If you have a GEM and MINERAL show, or convention that visits near your area, they will often have mineral identification for free or a low price for rockhounds. I will need to visit the next one here in Denver, to have some samples identified myself.