MINERAL NEWS

Köttigite/Parasymplesite: A new locality in Cornwall.

    Köttigite/Parasymplesite (Zn3(AsO4)2. 8H2O / Fe(AsO4)2. 8H2O) has previously been recorded from the Carrock Mine, Caldbeck Fell, Cumbria, and from Harriet's Shaft, Dolcoath Mine, Camborne, Cornwall. (See Green, D. I., Neall, T., Cotterell, T., and Leppington, C. M.: Symplesite and Parasymplesite from Cumbria and Cornwall, England. Journal of the Russell Society, 8(1) pp16-17. 2003).

    Recently it has also been found at West Wheal Mary Ann, Menheniot, Cornwall. West Wheal Mary Ann was a small lead working that closed in 1885. Sometime after, or prior to the closure the adit level was back filled with material which most probably came from the lower levels of the mine. In this backfill are several quartz/barites pieces which appear to be a conglomerate with pieces of bedrock (killas). Amongst this material are occasional small but well-formed crystals of sphalerite, which is unusually pure and with virtually no iron content. There are also small patches of arsenopyrite, pyrite and galena. The main gangue mineral in the mine appears to be dolomite, with aragonite and calcite forming as secondary minerals.

   The Köttigite/Parasymplesite was found in small pockets in this material. A specimen was sent to Manchester University where it was subjected to an EDAX scan. An intermediate between Köttigite/Parasymplesite was deemed as the most probable results.

    A photograph of the specimen is included below.

Köttigite/Parasymplesite, West Wheal Mary Ann, Menheniot, Cornwall.

(crystal spray approx 1.5mm in diameter).

A. Aldworth Collection.