What could this Arizona specimen be ?

[oredigger62]

First of all thank you for looking. These ( i have several) were found in Arizona , in the Mogollum rim country. I picked these up from the surface , they were not dug up specimens. I thought they might be copper so i loaded up my pockets til my shorts were falling off. Anyway , upon further inspection this is as far as i know, which isn't much. they are very heavy for size , the egg sized piece is almost 8 ounces. a rare earth magnet won't come close to sticking to it , and when i filed the end the inside is shiny chrome looking. these had a streak test and was a pink or faint red. Which is why i tried the various magnets. Many that i have showed these to at first thought good old iron until they failed the magnet test. The pics were taken with my camera on my phone , so my apologies for the quality. Thanks again !!!!! Lou

 

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[57chevy]

I would take one to the Geology Department at ASU. If they don't know what it is, no one will.

 

[l337scum]

Hmm this is interesting. Given then area I would think this could be copper based minerals of some sort. It looks like Chalcopyrite and Copper in the first picture but in the second it doesn't look like it at all. The streak is more indicative of pure copper. Does it always streak that way on white porcelain? Even when you try a different side or piece? Does the streak seem somewhat shiny or metallic? See if the brassy looking portion of the rock in the first picture streaks green or black. Also do any of the rocks you found have green on them at all? Look for green or blue to confirm copper. If you are daring you can break one of them open and see if a fresh face of the rock shows more clues.

 

[oredigger62]

all parts of this specimen streaks pink or light red . there is no secondary color on any of them . I love chalcopyrite and this certainly is not that. I was going to attempt to cut this open for a more in depth cross section until a guy suggested platinum... in which case a specimen this size would be worth quite a lot. I forgot to mention that a hardness test yields 9+ . streak tests are dull , not shiny or metallic. The first pic is what it looks like in sunlight , the second pic is under incandescent lighting. I would collect more " just in case" but i am not in Arizona currently , i am back east on another treasure hunt.

 

[l337scum]

all parts of this specimen streaks pink or light red . there is no secondary color on any of them . I love chalcopyrite and this certainly is not that. I was going to attempt to cut this open for a more in depth cross section until a guy suggested platinum... in which case a specimen this size would be worth quite a lot. I forgot to mention that a hardness test yields 9+ . streak tests are dull , not shiny or metallic. The first pic is what it looks like in sunlight , the second pic is under incandescent lighting. I would collect more " just in case" but i am not in Arizona currently , i am back east on another treasure hunt.

How interesting, the sunlight was throwing me off. I would send in some for assay for fun to see what it is made of. Hardness of 9 is also very interesting. Mohs of 9 would ruin a steel file used on it so that may be why you saw chrome as the file broke down. Also I don't think it would be possible to really test a streak with that as the plates are under 7 for hardness. Platinum would streak silver grey and be shiny. I am stumped. I am curious to see what it looks like closer up if you can get a higher resolution picture or a picture of a newly fractured piece.

 

[oredigger62]

i didnt file with a metal file . i used my makita grinder with a cutoff wheel. I will see if i can take another pic for you . probably try and post one tomorrow. as for the streak test , it was done on the unglazed side of the toilet lid. hope that helps

 

[DDancer]

Well its got my interest. As to hardness toilet bowl porcelain is in the 7 range for hardness just like tile. Off hand I'd say its a pyrite but the red streak doesn't agree though that does not rule out hematite being in the mix. Most pyrites are not magnetic unless they contain nickel or are mixed with magnetite. Its silver were you ground it off~ again this sounds like Arsenopyrite... did it smell like sulfur when you ground it down? If there were free copper in it I'd expect some greens or blues from oxidized material but I don't see any and your not reporting any so? hrm. A remote possibility is an electrum mineral. You can try a flame test and see what colors come of it as well. Another remote possibility is oroblanca~ white gold which is a silver/gold mix but that is typically only found down in southern AZ associated with the town and its placer deposites there.

 

[l337scum]

Well its got my interest. As to hardness toilet bowl porcelain is in the 7 range for hardness just like tile. Off hand I'd say its a pyrite but the red streak doesn't agree though that does not rule out hematite being in the mix. Most pyrites are not magnetic unless they contain nickel or are mixed with magnetite. Its silver were you ground it off~ again this sounds like Arsenopyrite... did it smell like sulfur when you ground it down? If there were free copper in it I'd expect some greens or blues from oxidized material but I don't see any and your not reporting any so? hrm. A remote possibility is an electrum mineral. You can try a flame test and see what colors come of it as well. Another remote possibility is oroblanca~ white gold which is a silver/gold mix but that is typically only found down in southern AZ associated with the town and its placer deposites there.

I was considering Arsenopyrite also but like most pyrites this would streak black. Also being that it is so hard, I didn't think that gold alloys like electrum were in the realm of possibilities.

 

[DDancer]

*shrugs* Its a remote possibility. Not to many minerals look like that and with Arizona's mineral deposites there are quite a few hybrids around. Heck I've even kicked the idea of a space rock around If you can get some chips off of it try a flame test to see if there is copper present~ green flame~ sulfur~ bright yellow.

 

[oredigger62]

i have numerous pieces that were collected as i said earlier so i can test probably 20 pieces and still have quite a few. Most are dime size , this one in the pic is the largest. I don't believe there is any gold in it , i really was happy when i believed it was copper. This one is strange because it seems to defy each test and the more that i try the more twists it produces. Maybe i will call it copperfield because it seems to be an illusion when identification seems to be at hand.

 

[Eu_citzen]

A hardness of 9 would not allow for a streak test. If you have quartz, do a new hardness test with that.

Eudialyte can have a white to light pink streak, but looks no where near this.
There are more minerals which streak pink, but none that I remember look metallic.

I'd say have someone look at it in person.