A Guide to the Mineral Data

The mineral data can be accessed through an alphabetical list of mineral names. Navigation is by a simple A-Z system. Information may also be retrieved by the Mineral Search facility. The data within each entry are split into the following categories.

Mineral Name This is the CNMNC – IMA approved spelling (see page below for details of the CNMNC)
Status in Wales Categories
Confirmed occurrence
Confirmed – type locality in Wales
Confirmed - 1st UK recording
Confirmed - 2nd UK recording
Confirmed - 3rd UK recording
Unconfirmed
Discredited
Discredited/obsolete mineral name
Distribution

A rough estimate of the abundance of the mineral in Wales e.g.
Ubiquitous
Widespread
Locally abundant
Uncommon
Rare
Chemical composition A general description of the chemical composition
Chemical formula The chemical formula as cited by the IMA
Chemical group The broad chemical grouping to which the mineral belongs (e.g. silicates, sulphides).
Verification This is the method by which the identification has been confirmed. The main methods listed are :
  • DTA – differential thermal analysis
  • EMPA - electron microprobe analysis (also referred to as EPMA in some text)
  • Microscope - (polarizing, reflected light or binocular)
  • IR -infra red analysis
  • SEM - scanning electron microscope
  • SEM-EDX - scanning electron microscope with energy dispersive X-ray analysis
  • SEM-WDX - scanning electron microscope with wave length dispersive X-ray analysis
  • Visual
  • Wet Chemistry
  • XRD - X-ray diffraction analysis
Localities The key occurrences of the minerals are listed here. This is not a comprehensive list but includes the best or most representative examples
Introduction An overview of the composition and occurrence of the mineral
Occurrence in Wales More specific information on the occurrence of this mineral in Wales
Geological context A guide to the geological setting in which the mineral is found. Some minerals may be present in many settings ( e.g. pyrite) whereas others are restricted to just one (e.g. glaucophane). These settings only relate to Wales. Further details of each setting are provided under ‘ Minerals where and why they occur’ .
Crystal system Minerals can be allocated to seven crystal systems, cubic, tetragonal, trigonal, hexagonal, orthorhombic, triclinic, monoclinic. Where there is uncertainty, some minerals may have more than one system listed, and others may be listed as amorphous, where the crystal system has not been determined.
References Reference to published information in scientific journals, books and magazines.
Pyromorphite
Pyromorphite
Pyromorphite
Pyromorphite
Pyrolusite
Pyrolusite
Powellite
Powellite
Posnjakite
Posnjakite
Pickeringite
Pickeringite
Phosgenite
Phosgenite
Pharmacosiderite
Pharmacosiderite