George uncovered this photogenic little millerite specimen last week and the picture caused quite a stir on Facebook over the weekend.
Labelled as being from the Windsor Colliery, Abertridwr near Caerphilly, Wales it displays a very pretty array of divergent millerite needles stemming from a single galena crystal with a "diamond" quartz crystal set to one side.
The display is almost too good to believe, but is definitely "au naturel".
These millerite specimens are well known from the South Wales coal fields - they are found in large rounded ironstone "pebbles" within the coal seams and dumped in the spoils.
The host is very hard to break open, and not every one contains treasure; amongst UK collectors there are many stories about "the one that got away" - where a beautiful millerite formation has become a shower of needles through the incorrect break or force. Usually after several moments of hammering in the pouring rain!
Noted minerals are,
Millerite
Galena
Sphalerite
Chalcopyrite
Pyrite
Siegenite
Associates
Quartz
Calcite
Baryte
Ankerite
Siderite
Hatchettite - wax
Good for Wales but sad for collecting, the coal tips where these were sourced have become depleted through land reclamation and development.
I am told there is similar habit millerite found in the coal fields of Pennsylvania.
