A geological ‘field trip’ to an old Cobalt mine in the Newlands Valley was suggested this afternoon. Details of which are outlined in a book bought from ebay (not by me!) for 99p a few months ago. The weather is wet (very), perfect for a fieldtrip, it has not stopped bucketing it down all day, so, hey, who wouldn’t leap at the chance of a rain soaked afternoon looking at random rock formations. I was going stir crazy indoors, so was the big hairy doggie…and there was a mention of Cobalt………..so, off we went…….
Cobalt is a hard, lustrous grey metal (may have helped to know this before we set off) and chemical element. Cobalt compounds have been used for centuries to impart a rich blue color to glass, glazes and ceramics. Cobalt oxide and carbonate are generally used in glaze preparation. Carbonate is weaker than oxide, also oxide tends to be coarser so speckles will appear in the glaze finish.
On the northern side of Sail Pass are the remains of a cobalt mine.The vein runs north-south and, although showing some cobalt, was found to contain a great deal more arsenic. The total yield of cobalt was only a few ounces (may also have helped to know this) and the venture was swiftly abandoned, but the spoils and the remains of the mine road/tramway can still be seen today at Stoneycroft Gill.
Julian lugged several large rocks back down the mountain, no Cobalt….just quartz intrusions….good examples of them though apparently!!
I have some clay taken from the side of the Stoneycroft Gill river bed which I will make into a slip when I return to the shed, it is an interesting yellow colour, so who knows what it contains….I think we can saftely say, no cobalt.