|
Click on the articles with a blue title to view
the abstract
|
|
GUEST EDITORIAL:
THE FUTURE OF MINERAL COLLECTING
John Mason
|
|
John Betterton
David Green • John Mason
|
|
MINERAL NEWS
Mick Wolfe
|
|
48 pages, 8 colour.
|
FAMOUS MINERAL LOCALITIES:
PENBERTHY CROFT MINE, ST. HILARY, CORNWALL, ENGLAND
John Betterton
with contributions by David I.Green & John Mason
Penberthy Croft Mine was noted as a locality for pyromorphite and mimetite
in the mid-nineteenth century. Since that time an increasing number of
minerals have been reported from the mine, making it one of the most diverse
and important mineral localities in Cornwall. An extensive range of supergene
minerals occur on the old mine dumps and fine specimens of bayldonite,
pyromorphite, mimetite, linarite, plumbogummite, carminite, and philipsburgite
were collected from the underground workings in the early 1990s. To date,
the locality has produced 90 confirmed mineral species including the first,
or joint first, recorded British occurrences of jeanbandyite, natanite
and segnitite. The type specimen of the copper lead arsenate mineral bayldonite
is from Penberthy Croft. Most of the supergene minerals are found in cavities
associated with strongly oxidised gossan in vein quartz, or in the blue
and green stained mineralised slate.
|
|
|
Above Left. Chalcotrichite
in quartz veinstone, the upper patch is 4 mm across and is partially
replaced with chrysocolla. Richard Bell collection.
Above Right. Radiating sprays
of bright green mixite up to 1.2 mm in diameter. John Betterton collection.
Photos: David Green. |
|
