FMF - Friends of Minerals Forum, discussion and message board

[Peter Megaw]

The Milpillas Mine in Sonora, Mexico has produced some exceptional brochanitite specimens recently. These range from stout (2-3 mm diameter) needles up to 4 cm long that are so dark green they look black...to forests of free-standing slender needles (1 mm in diameter) averaging 3 cm in length that have a wonderful emerald green color. I have seen matrix-free masses of interlocking crystals up to 20 cm across (the specimen NOT the crystals) and plates of blinding white matrix with forests of upright crystals. The best pieces are among the best ever for the species. Those who attended the Arkenstone gallery opening last weekend got to see an excellent suite of the best so far, and there is hope for more.

Milpillas is currently producing quantities of spectacular azurite, malachite, malachite psuedos after azurite...azurite on malachite after azurite (with unbelievably blue internal reflections bouncing off the malachite)...many of which rival classic localities like Bisbee and Tsumeb. It has also produced some very good cuprite, native copper and plancheite. The lapidarists even have something to smile about..."Sonoran Sunrise" a banded mixture of malachite, tenorite and cuprite infused rock is appearing as cabs almost everywhere.

But do NOT take Milipillas for granted...the mine is scheduled to exhaust the oxide zone in another 2-3 years and the flow of these wonderfulspecimens will dry up completely. Not to mention that the mining company is not happy with the collectors and is working overtime to put them out of business. In 10 years these will be hard to find classics...so load up now while you can!

[Gail]

I saw them at the arkenstone, they were exceptional.

[strahler]

Peter,

Are they in different zones in the mine, with less azurite and malachite?

Do you have, or have you seen pictures of the pocket zones? It would be really neat to see the zone that is producing these pieces.

[stumpy]

Another nice bit of free advertising for the Arkenstone!

[Jean Sendero]

Stumpy,
I do not like either "free adverts" but in this case, these are the best of the best. A few weeks back, I was fortunate to see Peters piece face to face and recently spoke with others that saw the "lot" and all are in "AH!!!!!!". I do not think that you can disregard the fact that as collectors, we are usually pleased to know where one can acquire a specimen from a new find and especially when these are likely amongst the best in the world. Thanks Peter.

[Peter Megaw]

Thanks for this Jean...I try to avoid plugging any dealer, but the reality is that folks want to know where the rocks are and I thought it better to make a public comment about that than deal with PMs...which have come anyway.

I do not know where these are coming from relative to the azurites and malachites, but the matrix is different and so is the chemistry, so I'd guess the location is too. The brochanites are on coherent monzonite and most of the others are on brecciated wallrocks.

I have seen no pictures of any of these pockets...they are mined clandestinely and quickly and the mine is very hard to get in to.

Here are a couple of shots of other Milpillas minatures for your delectation. Note the difference in the matrix on the first shot with the brochanite pictures

[strahler]

Peter,

Thanks for sharing the photos.

Milpillas is a very interesting deposit, let's see what is throws next. Hopefully Penoles does not clamp down too much on collecting, as these add to the treasures Mexico has produced.

[Peter Megaw]

I hear they have put video cameras at hoist landings so the miners know they're bing watched.

[javmex2]

Hello I have been lucky enough to contact some people from whom I have got some Milpillas specimens, and want to share with you these photos of some specimens of my collection.

[Ed Huskinson]

Nice specimens Javmex2, All about the same size, nice groups. Are they miniatures or thumbnails, or what. Just curious. Oh, and welcome to the Forum!!!!

[javmex2]

! Thanks Ed, the pieces are about 5cm. are all similar in size, do not identify the measures you mention, I'll be looking for information about such measures. and ask for some patience to adapt to the forum, greetings.

[Ed Huskinson]

The pieces are all either "toenails" or 'miniatures", both of which are nice sizes to collect. You have a good eye, and have picked up some good-looking specimens.

Keep up the good work.

Ed

[Peter Megaw]

Javier.. here's a guide to the "standard" size categories in the USA. Note that these are defined on the basis of how a specimen fits inside a cube of a specific size...AS IT SITS as YOU exhibit it...not if you can somehow make it somehow fit into the cube. The definition includes only the cube that the piece comes closest to fitting in...in other words it only gets to be in that one category, not that one and all the larger categories as well. A minature is a minature, it is not also a small cabinet and a large cabinet

Thumbnail: Fits inside a 1 inch (2.54 cm) cube
Miniature: Fits inside a 2" (5.08 cm) cube
Small Cabinet: Fits inside a 4" (10.16 cm) cube
Large Cabinet: fits inside a 6" (15.24 cm) cube

Anything bigger is a boat anchor!

The Tucson Show uses an additional category "toenail" that fits between thumbnail and minature... fitting inside a 1.5" (3.81 cm) cube. No-one else seems to recognize this category yet though.

Ed, Les...did I get this right?

[Ed Huskinson]

Yeah, Pete, perfect. When some of us (Tony P. Bruce, a few others) discovered this sort of overlooked size "category", we found that there were bargains to be had in this off-size range. Desafortunadamente, that is no longer the case. But it was a good run while it lasted. I gave up on boat anchors after my first collecting trip to the Blanchard Mine at Bingham, New Mexico. Still have the piece. It's stout, you can barely get your arms around it. Oh wait, there is also a large specimen of the low-angle brown scalenohedrons that come from the cavern underneath California Hill, Mariposa Mine, Terlingua district, Brewster County, Texas. I have a big one of those, as well.

Post more pictures of your brochantites. Or did you just pick up the one? Hope thnigs are gong well.

Ed

[Gail]

I took a photo of the shelf....and the label.

[javmex2]

thanks for your information it is good to know this for my, I just pick what I like and fits my hand, I rarely take into account size, take three things for my collection pieces: great brightness, color, and aesthetics, these three things result, magnificent specimens. although difficult to obtain.

[John S. White]

Javier:

Don't forget that in addition to providing sizes of specimens, it is also standard procedure to identify the minerals in the photos. I think we all are assuming that the tranparent crystal in the last photo is Baryte.

[javmex2]

Thanks John, will be placing all possible information the next time, sorry

[Jordi Fabre]