It looks like someone duplicated the Mackinaw district as the Leesburg district, but it's hard to tell. The Idaho Geological Survey map of mining districts does not show a "Leesburg" district but does show the Mackinaw district in that place. They should be merged.

This photo looks like it is under the wrong Skookum area. From the title saying "Skookum Copper Mining co, Roslyn, Wash." that would put it as being of the Skookum Mine in Kittitas co: https://www.mindat.org/loc-409751.html. Can someone please move this photo to this locality? 

At least in the western US, the term Mining District is applied widely. It can refer to a set area that was agreed upon by mines or the government, or just a loosely bounded region with a few mines. It can involve specific commodities, or multiple unrelated commodities. I've seen both metal and ...

I've been polishing some pyrite-bearing specimens recently, and have noticed something strange happening to them. On some, I will cut them in half, polish one half, and within a few weeks the polished half will have white fibers (some sort of sulfate) growing from the cracks around the pyrite and ...

Can anyone move this photo? It looks like it hasn't been taken care of. Just putting it under Lelande Mining district would be the best place for it.

Not to offer too much in the way of unwanted information, but the shaft in front of adit "layout" was very common for mines before exploratory drilling was popular. If you have a vein of unknown strike length and depth on a hillside, then driving an adit and shaft at a center point gives you a good ...

I understand the use of this for data science, but would it be possible to tag these these ultra-sub localities so they can be hidden by someone looking at a page if wanted?  When scrolling through a district or county page, I can imagine these new localities crowding out the actual main ...

I guess a fine dissemination of pyrite throughout the piece could do that, but from cutting this material I haven't seen that. I did some polished sections of the arsenopyrite from one of the mines, I'll have to try and track those down. It seemed that the coarse crystals did not decay as much, but ...

Some arsenopyrite does rot. The material from Monte Cristo Washington can crumble to nothing within a couple decades of exposure. I remember moving boxes of ore from the Mystery Mine that contained numerous pieces of arsenopyrite that had turned to powder. The acid had so thoroughly destroyed ...

Here is a photo of the matrix. The number on the back I put on when I got it, but it never really corresponded to anything. 

I have a piece of globular marcasite (possibly pyrite) on calcite that I am fairly certain is from Mexico, but I would love to know the exact locality on it. I got it in Tucson at one of the outdoor shows (Electric Park) about 8 years ago. The dealer was Mexican, and all of the other material he ...

I think you're really reading into that sentence more than necessary. I definitely have doubts about the locality due to the matrix but do not have a strong opinion on it going into mindat. It could be from Monte Cristo, but does not look like the material I have seen from there. Not many ...

The matrix certainly doesn't look at all like what I have seen from Monte Cristo, but I would not rule it out completely. The size is quite large, but not unbelievable for the district.Monte Cristo was largely dominated by one mine, the Monte Cristo Mine. That mine had the best realgar, but there ...

It's old, I know a replacement is coming somewhat soon. I don't think that machine though was ever meant to reliably detect trace metals, it's just a handheld unit. It's generally accurate if you take several shots of different spots on a rock and discount anything below 1-2%. 

The Stillwater and Mouat refineries are not far upriver from where you found this piece, and the makeup of this material is similar to what they process/ed. I'm not sure if it qualifies as "slag" exactly, but it being some product from the either of those plants (I would guess Mouat) would be ...

This piece is attributed to the wrong locality. There has been no autunite like this at the Queen Mine or nearby. I would guess it came from one of the mines in Spokane County or by Wellpinit, but I'm not sure. 

As far as the mineral ID I cannot say with too much certainty (I would guess titanite), but I know the locality. Ed Molsee collected that just above the upper portal of the mine in the canyon. I am fairly certain that the mine explored this mineralized zone and would count it as the same locality.

Can someone please fix this? The specimen has not been moved yet. There is no chance that is from the Deer Trail mine in WA.

It looks perfectly real. No mines around Telluride had much in the way of telluride minerals. They did however have an abundance of native gold that looks exactly like this.

Yeah, that is pretty normal for those waxy polishes. It likes to get stuck in cracks in the rock. It can be hard to remove, but I have gotten some out with a textile cleaning gun.

It looks like a polish. Something like Zam polishing compound frequently leaves waxy blobs like that in cracks.

If you want something quite bright, Wisdom lamps are some of the best that are used in the mining industry. Their only downsides are the traditional attachment and the lack of much brightness variability. The metal clamp attachment requires a cap with the right thing on the front (although the DMK ...

From doing some looking, I would feel fairly confident placing the piece as from the Big Buffalo Mine. It appears that it was worked somewhat recently by the Evans family, and one of them giving the piece to the collector you got the collection from is sensible. Labeling something from the "Big ...

I will have to do some research, but I think one of the mines in the Buffalo Hump district was called the Big Hump. The rock looks similar to the limited amount of ore I've seen from there.

The collection is at the Montana Bureau of Mines and Geology in Butte. It can be viewed, but it can be challenging to get an appointment. It consists mainly of tens of thousands of samples in narrow drawers.http://mbmg.mtech.edu/Information/Collections/Anaconda-Collection/main.asp

There is a bit of error inherent in converting the format that the BLM gives into coordinates. The "Mer Twp Rng Sec 23 0440N 0180W 024". represents an area, while the coordinates are just a point. The Mer Twp etc. notation is kind of hard to get used to but it basically places you closer and closer ...

I am not sure on the note in the mineralogical record, but the Anaconda collection is generally seen as one of the best primary sources on the mineralization of the district. They have a few samples of rhodochrosite attributed to the Leonard, with level and stope information attached to them.I ...

Since this is an unpatented claim, locating it precisely is difficult. They give 3 sections that it is in however, so this one is easier than most to find since you can just go off of the common corner. Based off of the claim number given, it would be located around: 38.06854, -108.81580 ...

While I agree that the Emma is by far the most notable rhodochrosite occurrence in Butte, I would not rule out the Leonard for this specimen. The Leonard did have rhodochrosite, or at least there are pieces of rhodochrosite attributed to the Leonard in the Anaconda collection. I have not seen the ...

I am by no means experienced with this area, but the photos posted here seem a bit odd. It seems strange for a motherlode deposit like this to have this sort of material together. The large galena crystals are especially off. Does anyone know if these are valid?I would guess that this is a mistake ...

While it is not incorrect, it is confusing as a name. The city and county have merged their governments and are officially called "Butte Silver Bow" on government doccuments. Many people living here (including myself) will call it "Silver Bow county" though. This is especially true for places in ...

Or bullet shards. Those can look somewhat similar to the first photo.

It is, but where exactly the Matthews property is I am not sure. If I recall correctly, Bart found the minerals in a piece of core from there. He said it was somewhere around the Lovitt and Cannon Mines. From his book, he lists aurostibite as existing in the Cannon Mine. He also lists fischesserite ...

I doubt there is anyone out there who can place the locality with certainty. The author of that book is dead, and I assume whoever collected the piece is as well since it was in a very old collection.  

I do have that book, and it is one of the most reliable sources for the state. That being said, the existence of the locality is due to a series of assumptions that were made I believe. In an old university of WA collection there was a piece with the minerals entered into the locality with a label ...

Would anyone be able to remove them from that locality then? I'm guessing the person who posted them was searching for something like "unknown location" saw "unknown snoqualmie pass mine" and didn't read past the "unkown".

I am not sure where this piece is from, but without any evidence saying it is from an "unknown snoqualmie pass mine" doesn't make sense. The user appears to have added many other random mineral photos to this locality, which makes this one even more doubtful. This appears to be the only one that ...

It's here: https://www.mindat.org/loc-406389.html

The Black Pine was almost completely wiped out by reclamation. The dumps are all buried and all that's left are some buildings. There's not a whole lot as far as crystalline specimens to find around Granite either, but the dumps are still there and it's a neat place to check out.

Looking at the individual atoms in a molecule while ignoring the others generally isn't the best way to evaluate it. Lead oxides, carbonates, and the like are seriously problematic since they are pretty soluble and your body will readily absorb them. PbS (galena) is very insoluble in the conditions ...

Thanks everyone! The LW UV trick worked great, and it now clearly reads "Grape Ore, Mammillary Limonite, Pendill". I'm glad to hear from some local experts that this material fits what could come from the Pendill/Lucy. Here is the rest of the rock.

I got this piece recently and was wondering if anyone knew what this label might say. It is a piece of botryoidal iron oxides labeled "Grape Ore" at the top. At the bottom is typed "Mine, L. S. Mich. Wettstein's Museum Negaunee" I'm assuming the "L.S." refers to Lake Superior. Any guesses on what ...

I've run into similar issues with the search function, but with a name as common as Homestake though you're bound to have an incredible amount of results. I was able to find it by searching "Homestake Mine South Dakota". It would be interesting to see if there was a way to rank search results ...

I know this wasn't directed to me, but I know a bit about the metal deposits on the Middle Fork. It consists of a bunch of breccias with blebs of sulfides, but none of them were ever large enough to justify mining them. The Clipper zone on the north side of the river had some early development done ...

I have some ore that I was wondering if anyone could figure out the locality on. It is mostly breccia fragments that are cemented by cuprite. One piece of the breccia is being replaced by cuprite and native copper. It measures 4"x2" on the face. There are several pieces of this in the drawer that ...

It's completely legal to sell unpatented claims, you're just selling the mineral rights. A fair sized industry has sprung up though exploiting the lack of knowledge of people about claims in a scamm-y way. They manage to stay mostly legal however by including disclaimers and only implying what ...

It seems like that is the only really hard one. The other ones that crossed the counties (Humboldt, Revenue, and a tiny bit of Camp Bird) had one major portal in one county so they are easier to classify. The cross-county openings of these are mostly them intercepting older workings or non-haulage ...

That report has some good references, but I wouldn't use it to group localities here, especially in the San Juans. It lacks definite boundaries for lots of them, and there is lots of overlap. They pulled information from lots of different sources from different times so confusion is going to ...

Right now I'm working on sorting out the Ouray/San Miguel mess. There are mines that have no contact with one county that are listed in the other, so I'm fixing some of those. I haven't gotten to the Red Mountain district yet, but I'm slowly moving there.

The Telluride district is just in San Miguel county. What makes it difficult is that some of the mines (Idarado most notably) go into Ouray county. The Ouray district would not be considered a subdistrict to it.