Matlock / Via Gellia. Sphalerite etc

[Brains]

On various trips over the years I have noted the presence of layers of fine grained sphalerite, almost black when underground drying to a pale brown. The grains are quite fine and don't typically have a good crystal shape. On one occasion I found a small piece of well formed sphalerite with good growth habit in the deads on the floor of Snake mine.
I wonder how many Peak mines actually contain small amounts of zinc minerals? The Owd Man would have easily recognised heamatite, pyrite, calcite, fluorite, baryte and galena as common in the veins. Even hemimorphite is quite distinctive. Fine grained granulated sphalerite can look at first glance like dark fluorite, rotten wood or sooting, so maybe overlooked?
On a recent visit to a well known Matlock mine, I also noted some very fine black "ground pepper" speckles on a broken vein surface. I have seen similar pepper effects in Alderly Edge, Great Orme and Clive Mine where it's associated with pink cobaltian calcite and is an ore of cobalt. I am unfamiliar with cobalt primary minerals in the Matlock/Peak area, and certainly have not seen the secondary cobaltian calcite. Maybe just traces of iron oxide after pyrite
Does the hive mind know of any reports or research on sphalerite or even cobalt minerals in the Matlock Peak ore field?

 

[AR]

Your starting point for Peak District mineralogy is this - https://pdmhs.co.uk/MiningHistory/B...nerals of the Peak District of Derbyshire.pdf though there's Roy Starkey's "Minerals of the English Midlands" published more recently.
Zinc mineralisation is pretty common in the Peak, I don't know whether sphalerite was deliberately extracted from the mines but smithsonite (calamine) definitely was for brass-making, there are records of it being mined in the Bonsall area and at Hard Rake near Sheldon.
I'm not aware of any cobalt mineralisation in the Peak, even at Ecton.

 

[Brains]

Your starting point for Peak District mineralogy is this - https://pdmhs.co.uk/MiningHistory/Bulletin 12-1 - The Minerals of the Peak District of Derbyshire.pdf though there's Roy Starkey's "Minerals of the English Midlands" published more recently.
Zinc mineralisation is pretty common in the Peak, I don't know whether sphalerite was deliberately extracted from the mines but smithsonite (calamine) definitely was for brass-making, there are records of it being mined in the Bonsall area and at Hard Rake near Sheldon.
I'm not aware of any cobalt mineralisation in the Peak, even at Ecton.

Thanks for the link and advice. Reading it now
Realised I meant pyromorphite, the green lead phosphate rather than the dry bone zinc mineral hemimorphite I mentioned above. Oops

 

[AR]

Forgot that the final phase of mining at Magpie was going after sphalerite, which apparently became a lot more abundant than galena in the lowest levels of the mine, but in earlier centuries, calamine was the desired zinc mineral due to its usefulness in making brass. Metallic zinc is awkward to produce as the temperature at which the oxide will reduce to the metal in a smelting furnace is higher than the temperature at which pure zinc sublimates, whereas you can make brass by adding calamine to molten copper in a reducing atmosphere.
Hemimorphite can form some attractive "bowtie" crystals, I've seen some in the Ruggs Hall series of Ball Eye.

 

[owd git]

Forgot that the final phase of mining at Magpie was going after sphalerite, which apparently became a lot more abundant than galena in the lowest levels of the mine, but in earlier centuries, calamine was the desired zinc mineral due to its usefulness in making brass. Metallic zinc is awkward to produce as the temperature at which the oxide will reduce to the metal in a smelting furnace is higher than the temperature at which pure zinc sublimates, whereas you can make brass by adding calamine to molten copper in a reducing atmosphere.
Hemimorphite can form some attractive "bowtie" crystals, I've seen some in the Ruggs Hall series of Ball Eye.

I assume this all ties in the reason for the calamine mill on cromford meadows (now just a vague outline footprint .) P.S. Hi Adam.

 

[AR]

Hi Ric, yes - the mill was processing calamine from the surrounding area, but there's not a great deal of records of the industry, usually mentions in passing in dealing with lead mining matters, and of course the calamine belonged to the landowner, not the Duchy of Lancaster so wouldn't fall within the purview of the Barmote Court.