New specimens

[TomFerry]

a few photos of my most recent finds.

Calcite blades
Rhombohedral dolomite
sphalerite
Image 5 is the back of image 3, suspect the host rock is mudstone .

All from north wales

 

[Roy Morton]

Pharmocosiderite from Pedn-an-Drea mine Redruth. The sample also contains Chalcedony and Cassiterite (not pictured)
Largest crystal is 3mm

 

[Roy Morton]

Green spheres of Bayldonite up to 2mm on white Mimetite from Penberthy Croft Gwinear Cornwall. 1998

 

[AR.]

Pharmocosiderite from Pedn-an-Drea mine Redruth. The sample also contains Chalcedony and Cassiterite (not pictured)
Largest crystal is 3mm

Nice sample; I would have glanced at that and assumed it was fluorite!

 

[neutronix]

Nice sample; I would have glanced at that and assumed it was fluorite!

If you are lucky, pharmacosiderite crystals develop small {111} faces in addition to the common {100} cubes. The point group symmetry of fluorite (m-3m) permits 8 of these at all the corners, however, the point group symmetry of pharmacosiderite (-43m) only permits 4 at alternate corners. Diagnostic if they occur, but the law of sod doesn't prevent equal development of {-1-1-1}...

A diagram of a Cornish pharmacosiderite illustrating the {111} development is shown In Dana's System of Mineralogy, Volume II, page 996.

 

[TomFerry]

Melanterite .

Have to keep this in sealed containers or it dissolves .

 

[Roy Morton]

Melanterite .

Have to keep this in sealed containers or it dissolves . View attachment 612View attachment 613View attachment 614

One of the few minerals that can be identified by taste along with its sister chalcanthite.
It tases emmetically awful