In the 1990s while active underground and living in Coniston I was a member of a well-known Mining History Society. In articles and general chat it was often commented that the green minerals seen in the Coniston mines were Malachite and the blue were Azurite. Being a bit skeptical if this was the case I contacted a good friend at the B.G.S. who had many years interest and research with Coniston minerals. I asked him to write an article about what post-mine minerals were present and the processes involved…which he kindly did.

It turns out most of the post-mine copper minerals are Sulphates with the greens generally Brochantite and blues either Langite or Posnjakite.
This old article is now copied into the Coniston copper mines page so anyone interested can see what post-mine minerals have been identified and the processes that produce them.

http://www.aditnow.co.uk/documents/Coniston-Copper-Mine/Post-mine-mineralisation-at-Coniston-.pdf 
Jeff

It's an interesting one for sure. Many people also include chrysocolla.

The "gunge" (flowstone) is largely silica and the variable amounts of colours in it are from impurites, whether iron oxides, copper sulphates/carbonates or more exotic species. Since it is amorphous rather than crystalline, it suggests that it is not pure. This is what I would expect.

From an analysis point of view, if you whack it in XRF, you are going to get a pretty random amount of elemental ratios which would be foolish to assign to a definite species. If you whacked it in XRD, you're going to probably not gain any meaningful patterns. If you looked at it with a microscope, you might see some characteristic crystal structures.

The other day, we were in a local copper mine and noted the whole variety of different hues. Some of the darkest indigo seemed to be crystalline. In this case, I'm sure that amongst the amorphous silica, there were various lumps which had become nucleation sites for various crystals to grow within the gunge. This is what I would expect if you looked at these slimes in greater detail. Silica chains with aggregates of "stuff" hanging off them.

I would personally not assign any greater chemical identity to them than "Copper carbonate/sulphate/whateverelseate rich silica gunge"

I thought the very sulphatey looking stuff was likely to contain a high yield of copper and set about smelting some. The yield was very shocking indeed (verging on nothing) because the copper salts are associated with the silica and are hence insoluble. You can't dissolve and filter and re-crystallise and then reduce to the oxide and then smelt.

I did cook a load of it on the stove (doors open, SOx fumes) and it went red, indicating the presence of copper oxide, but once this was done, it was impossible to separate the insoluble oxide from the residual silica.

I think the best place for it is on mine walls.

I have noted that the really awesome blues are in granite. I assume the silica is liberated from rotting granite in a very fine manner next to weathering decomposing pyrite (forming H2SO4 and then CUSO4) which then mixes and accumulates.

The greens I have not noticed in Granite (apart from where it could be botallackite (Cu Chloride based). I wonder if the greens are anything to do with weathering carbonate rocks (limestone). I have yet to see any really big amounts of greens, but I gather there are some in Wheal Edward (calstock) and Redmoor (callington) and perhaps this would be enough to conclude any relation from the country rocks around there. Or whether it was being mobilised from existing carbonate lode material.

Allihies has fantastic copper staining. Mountain Mine has superb Blue/Green (Langite) and Green Brochantite. Dooneen Mine is very intersting, its a scramble down to the beach of about 80 feet, need a rope, you pass through the mine and out into a cove where there is a cliff covered in Bottallockite, apparently the lode was noticed from a boat!!
There is a paper on the copper salts of Bunmahon (Tankardstown) Co. Waterford by Dr Moreton, most of the staining was indeed amorphous, he concluded that this gel eventually becomes chrysocolla. Will need to try upload a copy