[Rockhounds] identity question

[Andrew Turner]

I concur with Alan.  You can often tell what district (and sometimes individual mine) the galena is from based on its associates, luster, and size.  If you had some photos, that would be extremely helpful.

The galena from the Viburnum trend, especially from the Buick and Fletcher Mine Mines (where much of it is coming out), is typically very massive and shiny with often large crystals.  There aren't many associations, especially with the larger crystals.  You do get a little calcite and minor chalcopyrite and sphalerite (and one wall in the mine with siegenite and bornite!) but that is typically rare if the galena is large or massive.  Matrix is all dolomite.  Sweetwater Mine is different in that is has more voids, so you do get larger calcites and chalcopyrite.  Since the galena from here is often massive without many associations, they typically aren't worth too much (unless you have a giant crystal, have one with iridescent chalcopyrite, or it has siegenite or large calcite all over it).

The galena from the Tri-State District (Joplin, MO, Baxter, KS, and Pitcher, OK) is typically smaller with well-formed and duller crystals.  They can be more octahedral as well.  However, you often get well-formed and large, colorful, sphalerite and calcite crystals (sometimes huge ones).  It is very different from the Viburnum stuff, although some Sweetwater stuff can look a bit like it.  These specimens can go for higher values due to associations and (somewhat) rarity.  They are usually pretty easy to recognize.  Galena from the Old Lead Belt in MO can also look like this at times, but specimens from there are much rarer.

The galena from the other "Tri-State" district around IL and WI can be somewhat rare.  It tends to be duller and less well-formed.   It also can have sphalerite and fluorite with it.  Value of specimens from here varies wildly and depends on exact location (rarity) and associations.

Hope this helps.

Andrew Turner

________________________________
From: Rockhounds <rockhounds-bounces at rockhounds.drizzle.com> on behalf of Alan Goldstein <deepskyspy at outlook.com>
Sent: Monday, June 3, 2019 8:09 PM
To: Rockhounds at drizzle.com: A mailing list for rock and gem collectors
Subject: Re: [Rockhounds] identity question

Going through Steve Garza's collection, I've encountered galena from northern Illinois, Viburnum Trend and the old Tri-State District localities. Associated minerals make it easier to see differences. However, bare galena might prove a bit more problematic. I will make a generalization - the northern Illinois galena has a dull luster, the V-T is usually more lustrous, and the O-TS material is almost always intimately associated with sphalerite or chalcopyrite.

I'm sure there are some matrix differences since they occur in different rock formations.

I'd suggest perusing mindat and look at photos of galena from those localities to see if you find something that looks similar. I've done that a lot to confirm or reject Garza minerals w/o labels.

I expect to be posting a new list from Steve's collection tomorrow or a day after now that the Clement Museum show is over.

Alan

-----Original Message-----
From: Rockhounds <rockhounds-bounces at rockhounds.drizzle.com> On Behalf Of Dennis Buffenmyer
Sent: Monday, June 3, 2019 8:34 PM
To: Rockhounds at drizzle.com: A mailing list for rock and gem collectors <rockhounds at rockhounds.drizzle.com>
Subject: [Rockhounds] identity question

I am going to ask; what I hope is not a stupid question. Is there any way , of making a distinction, by visual means, of whether a piece would come from the viburnum trend, or a Mississippi Valley lead zinc ore deposit. I have a wonderful looking galena specimen of some size that generally appears to come from somewhere around there, and was hoping to better identify it. Would the matrix be obviously different? I know from what I have read that one of the principle differences between the two is the means and speed of precipitation of minerals.  Which makes one wonder, is that a BIG small xtal or a small big one. I would be perhaps more sure of an id based on analytical means, but is anyone really going to spend the money to confirm that a particular specimen does or does not come from a particular source, and specifically if the specimen may only be worth $100 if the location is known?? In buying a specimen are there any assurances to be aware of?

Enjoy the day

Dennis Buffenmyer

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