FMF - Friends of Minerals Forum, discussion and message board

[al mar]

Hello,

On my last trip to Bolivia, in 2016 I got one sample of vauxite that supposedly came from the Huanuni mine. I got that sample from a mining engineer that works in the mine, and taking minerals from Huanuni is complicated because it is a state-owned mine. He told me that the sample of vauxite was collected personally by him inside the mine of Huanuni.

I mean there was no gain to say that it came from Huanuni and not from Llallagua, My question is because in Mindat Vauxite appears as discredited from Huanuni. Does anyone have news of other samples of vauxite from Huanuni? The samples collected come likely from the -80 level Patiño section if it helps.

[John Betts]

I once had a specimen of blue vauxite from Miraflores Mine, Huanuni, Oruro, Bolivia that came from the collection of Eugene Sensel, originally acquired from Richard Kosnar.

[alfredo]

Indeed, as John wrote, there were many good vauxites originally marketed by Richie Kosnar as from "Miraflores Mine, Huanuni". But I think there was some confusion in the locality here because, over the 12 years I worked in Bolivia I could never find a "Miraflores Mine" in Huanuni, nor even a vein named Miraflores anywhere. There was a miners' residential barrio in Huanuni called Miraflores, but it had no mine or mineralization. Then one day I accidentally stumbled into a Miraflores mine in the town of Uncia, about 40 km southeast of Huanuni, and this Miraflores turned out to be a back entrance to the famous Siglo XX deposit in the neighboring town of Llallagua, so it could very well be true that phosphates like vauxite came out of this Miraflores mine. Furthermore those alleged Miraflores vauxites were originally on a typical Llallaguan allophane matrix, which is unstable and crumbles away, leaving those beautiful thin blue vauxite crusts with the empty botryoidal-shaped casts on the back, which is common in Llallagua but quite untypical for Huanuni. And showing photos of these to miners and dealers universally elicited the response that they must be from Llallagua, not Huanuni.

My experience with the psychology of Bolivian sellers is that they tend to tell you what they think you want to hear about locality info. So if you drop a hint that you are interested in minerals from Huanuni, then they are likely to tell you the specimen you are looking at is from there. And mine engineers and geologists tend to have lots of specimens in their office from other mining districts in Bolivia too, not just the one they are currently working at.

All that being said, it is of course entirely possible that vauxite could show up at another Bolivian tin mine, not just Llallagua. After all, for a very long time phosphophyllite was known only from the Cerro Rico but then showed up at two other unrelated mines, and ludlamite was known only from Huanuni, but then good crystals showed up at Colavi too. So perhaps vauxite in Huanuni too? But in order to believe it, I'd need to see it in situ in the vein underground, or at least see some specimens with some typical Huanuni associate minerals or Huanuni matrix rock (like for example ludlamite, siderite, hisingerite, elongated quadratic cassiterite crystals, etc). Perhaps I'm just getting too cynical in my old age. ;))

[al mar]

Here I have one photo of those vauxites if it helps.