A Bagley collection introduction.

A Bagley collection introduction.

I have a very large basement area, and this photograph is my store of all things geological, including my collection of rocks, fossils, and minerals. There are many hundreds of mineral specimens, and it will take me a long time to put all of them on the website. Many  minerals  have been collected here in the Central Wales Orefield (CWO). Unfortunately many of the sites have been overgrown, or "landscaped", leaving only a handful of local sites which may still yield the odd specimen.  The listed specimens can also be viewed in picture format by accessing the "Bagley collection" on the home page.

Carborundum

Carborundum

I offer no apology for including carborundum in my collection. I saw the specimen on a market stall amidst the bric a brac priced at £10, and I could not resist buying it. Carborundum is of course a manufactured mineral made from silicon and carbon. and is also known as silicon carbide. SiC.   The method for producing carborundum was patented in 1893 by Edward Goodrich Acherson, and since then it has been one of  the most important minerals in many production processes.  The life of Acherson is fascinating, and I recommend that the reader should take a close look at his activities. The irridescence is the result of a silicon coating on the mineral surface.

Malachite with Chrysocolla

Malachite with Chrysocolla

Malachite is a copper carbonate hydroxide with a formula of  Cu2CO3(OH)2. Chrysocolla is a  hydrated copper phyllosilicate mineral, and mineraloid. The formula is highly complex, and so it is omitted. This specimen of unknown origin is composed of a bed of very dark green microcystalline crystals of malachite, overlain with an encrustation of mineraloid chrysocolla in very small botriodal form.

Ferroan dolomite

Ferroan dolomite

Ferroan dolomite is a way of describing dolomite which has an iron content, which imparts a rusty brown colour. There is a running discussion on whether a particular specimen is either Ferroan dolomite, or Ankerite. A true analysis can only be conducted in a laboratory. I am inclined to believe that this specimen is Ferroan dolomite, both from appearance, and because it is recorded as being present at the location by the National Museum of Wales. I collected the specimen from Henfwlch mine, Nant y Moch reservoir, in central Wales. It is composed entirely of Ferroan dolomite,  Ca(Mg,Fe)(CO3)2   with inclusions of  fractured wall rock, and would be described as an example of hydraulic brecciation.

Calcite, nailhead.

Calcite, nailhead.

Calcite, Calcium carbonate , CaCO3  Calcite is a very common mineral, found in nearly all geologic environments. This specimen is a druse of "nailhead" calcite crystals, on a rhodochrosite base. The crystals have a dusting of a black mineral, probably goethite. The rhodochrosite shows just a hint of pink colouration in places. It was collected from South mine, Broken hill, New South Wales, Australia.