Apex Mine, Utah Cu/Zn carbonate

I recently obtained this specimen from Apex Mine, Jarvis Peak, Tutsagubet District, Beaver Dam Mts, Washington Co., Utah, USA. It is 21 cm across the longest dimension, and came with a label from 1958 identifying it as "Aurichalcite w/Azurite." The seller I bought from subsequently identified it as malachite with aurichalcite. I am not aware of any analyses of this specimen beyond visual inspection. The color in the attached pictures is almost perfect (at least on my monitor).

I can readily identify areas of light-blue, acicular aurichalcite crystals. These show up near the top of the specimen in the photograph that depicts the entire piece. However, the greenish-blue mineral present across most of the specimen does not appear to be malachite or azurite to me. It is too green to be azurite, and too blue to be malachite. I am curious as to whether it might be rosasite.

The "matrix" appears to be mostly whitish to pinkish smithsonite, with some areas of pink crystallization. The copper/zinc carbonate and pink smithsonite combination is a classic Apex Mine association, so I am pretty certain that the locality is correct.

I have a couple of questions for the Mindat brain trust: (1) is there an easy test to make a determination as to whether this "malachite" is actually rosasite or some other carbonate?; and (2) does anyone with experience with Apex Mine pieces or Zn/Cu carbonates have any opinions based on the attached pictures?

Thanks for the help!

James

Hi James,

I think Rosasite is a possibility, although I'm not familiar with it's mode of occurence at Apex. We'll see what others think. Good luck with it.

Ron

Thanks Ron.

Hello James,

I have a specimen of cobaltoan smithsonite with aurichalcite and rosasite from the Dixie Apex mine. The specimen that you have pictured does have some similarities to the piece that I have. I think that rosasite is more likely than malachite. It seems that the malachite from this locality usually occured with azurite. I certainly do not see any azurite on your piece.

Brent

If you had access to a microscope you may find occurences of all. That's a nice looking large piece! Would be tough to get it into the field of view. Do you have a loupe?
Joe

Thanks for your thoughts, Brent.

Joe, thank you as well. Through my loupe I can see a few scattered and small (5 mm across or so), distinctly "greener" areas that might actually be malachite (or something else). For the bluish-green mineral in question, I still cannot discern whether it is rosasite or something else.

It sure looks like a fine Rosasite!

It looks like all my rosasites from there.

Rick
I know I am in my own little world, but everyone knows me here.

Thanks for all the replies thus far.

Brent and Rick, I also wanted to separately thank you for uploading so many pictures of minerals from Utah localities. I collect primarily Utah minerals, so it is nice to see others have to show (especially when they are so prolific!).

James,

Do you live in Utah? What is your connection to Utah minerals?

Rick
I know I am in my own little world, but everyone knows me here.

James,
It just occurred to me who I was talking to. Some days, it seems I would loose my head if it wasn't attached.

Rick
I know I am in my own little world, but everyone knows me here.