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Improving Mindat.orgNot from Phoenixville

12th May 2015 21:51 UTCJeff Weissman Expert

Wulfenite, Mimetite

Phoenixville Mining District, Chester County, Pennsylvania, USA

This wulfenite on mimetite is certainly not from Pennsylvania

13th May 2015 01:00 UTCMark Heintzelman 🌟 Expert

Mimetite from Wheatley is so uncommon that I would balk at offering much of an opinion on this piece merely from a picture. A very unusually Wulfenite color, form and size for the district as well, but although wulfenites were primarily bright orange, even fire engine red, there were observations of a range of forms and colors, even pyramidal and grey (recall the mistaken Stolzites from there). Anecdotally, one of my Pyromorphites from Ecton mine has a few wulfenites very much identical to these, albeit much, much smaller.

It is certainly a pretty a-typical specimen for the district, but could it possibly be just extremely rare? I just can't feel confident enough to second that it has been "misattributed" (questionable yes, in need of a closer examination).

Additionally, I thought that all the Pennsylvania specimens from the Academy of Natural Sscience, Philadelphia went to the Carnegie collection? I also have to wonder why such a rare specimen, as this is purported to be, would have been simply released for resale (?)

It is worthy of a raise eyebrows or two at least.

MRH

21st May 2015 18:35 UTCJeff Weissman Expert

Mark - I have never seen mimetite (or pyromorphite) in this habit or color from Phoenixville, the matrix is a bit off for the district also. The wulfenite crystals reminds me of some Mexican or Arizona localities. Gordon describes mimetite, from Phoenixville, as occurring as "colorless, yellow, or greenish yellow crystals similar to pyromorphite" and wulfenite as "bright yellow or red" crystals. Albeit there is a wide range of habits of these minerals at Phoenixville, but this specimen is not amongst them.

21st May 2015 19:59 UTCMark Heintzelman 🌟 Expert

Yes Jeff,

Mexico is the first thing that comes to my mind as well, and I am highly skeptical of this piece too. One thing that dissuades me is that it came out of the ANS, Phil collection, which did have some very exceptional material. Could some unscrupulous individual have swapped it out for a cheap mexican piece somewhere in it's history . . . it wouldn't have been the first time. Mostly, I'm just saying I don't personally have enough experience with Phoenixville mimetite specimens to feel absolutely confident from this pic alone (matrix as you say, also looks dodgy, but an in-hand exam could tell a better tale).

Tentatively, of course I'm with you on this, and not sure that it should remain in the gallery until more closely scrutinized. It's certainly not representative of what little I've seen. All I've ever seen were tiny glassy yellowish-green crystals that were somewhat barrel shaped and off-matrix (not much help). Distinct enough from the district Pyromorphite, but not so much for the species itself.

MRH

21st May 2015 22:18 UTCJeff Weissman Expert

I'd suggest that this image be moved out of the Public Galleries for the time being

22nd May 2015 15:40 UTCReiner Mielke Expert

I am with you on this, when something is in doubt move it to the private gallery until proven otherwise.

22nd May 2015 18:12 UTCUwe Kolitsch Manager

Now user-only (incl. child photo).

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