Introductory Notes
The Minerals
The minerals pages of this website provide notes on each of the mineral species reported from Tsumeb. In general, only species names currently approved by the International Mineralogical Association (IMA) are included although, where identification of minerals to species level is problematic, group, sub-group or series names have been included. Note that group, sub-group and series names, as well as synonyms and varietal names, are italicised throughout.
Each mineral is described under several headings:
Status at Tsumeb: (see below for definitions.)
Type mineralogy: (a brief history of the discovery and description with key literature references; only provided for minerals for which Tsumeb is the type locality.)
Abundance, occurrence, and distribution: (see below for definitions.)
General notes: (an account of the history and mode of occurrence of the mineral, with notes on the paragenesis and descriptions of important specimens.)
Associated minerals: (an alphabetical listing of associated minerals observed or reported as occurring with the title species.)
Pseudomorphs: (list of (a) species after which the title mineral forms pseudomorphs and (b) species that form pseudomorphs after the title mineral.)
The following definitions are used: Status at Tsumeb is one of the following:
Believed valid: The species is adequately documented, ideally in the peer-reviewed literature or, alternatively, from a source believed to be reliable and credible. The means of identification are stated and, ideally, analytical data has been made available for inspection.
Questionable: The mineral has been reported from Tsumeb, perhaps in sources that have not been peer-reviewed. In some cases the reports, peer-reviewed or otherwise, have failed to provide either adequate analytical information or convincing evidence of a Tsumeb origin for the material studied.
Doubtful: Although the occurrence of the mineral has been reported there are reasons to doubt its occurrence at Tsumeb.
Discredited: A mineral previously reported to occur at Tsumeb has now been officially discredited or its presence at Tsumeb has been shown to be a case of incorrect identification.
Abundance is one of the following:
Common: Specimens are generally available to collectors (anglesite, cuprite, dioptase, mimetite).
Somewhat rare: Specimens are available to serious collectors but are likely to require a diligent search (adamite, baryte, gypsum, linarite).
Very rare: Specimens are generally hard to come by although a serious long-term collector of Tsumeb minerals might reasonably aspire to own an example (alamosite, phosgenite, schneiderhöhnite, scorodite).
Extremely rare: Few specimens are known. A serious long-term collector of Tsumeb minerals would struggle to obtain an example (bartelkeite, johillerite, queitite, vanackerite).
Occurrence is stated as one or more of the following: rock-forming (detrital); rock-forming (diagenetic); rock-forming (igneous); hypogene; supergene; post-mining. Please note that the term “supergene” is used sensu lato to describe all minerals arising from the oxidation of primary (hypogene) ores.
Distribution is stated as one or more of the following: first oxidation zone; second oxidation zone; third oxidation zone; sulphide ores; country rocks (dolostone stratigraphy); country rocks (feldspathic sandstone); country rocks (shungite); country rocks (kersantite); first oxidation zone; second oxidation zone; third oxidation zone; undetermined.
Please note that information on abundance, occurrence and distribution is not provided for minerals of questionable, doubtful or discredited status.
Specimens (and Pseudomorphs)
Each mineral specimen (or pseudomorph) is represented by one or more images and described under a range of headings (although please note that there are very few specimens for which a full range of information is available and that empty information fields are not displayed on the specimen pages). The headings are:
Precursor: Indicating (for Pseudomorphs only), the original (pre-replacement) mineral species. In some cases, the precursor mineral is “undetermined”.
Associated minerals: An alphabetical list of associated minerals occurring on the specimen. Species for which the identification is uncertain are marked “(?)”.
Size: A size category (cabinet, miniature, thumbnail or micromount) and a maximum dimension in millimetres are given. TMN defines cabinet specimen as > 50 mm; a miniature as between 31 and 50 mm; a thumbnail as < 30 mm and a micromount as a specimen of < 30 mm requiring magnification in order to view the principal mineral.
Location in the mine: Oxidation zone, level and stope number are presented for specimens where this information has been credibly recorded.
Collection: The owner of the specimen, either individual or institutional, is identified along with the catalogue number assigned by the current owner.
Entry type: The item is identified as either a Specimen or a Pseudomorph along with a unique “TSNB” number by which it can be accessed or recognised in the database.
Description: A detailed description of the specimen, its provenance and significance.
Our long-term objective is the presentation of a large and comprehensive selection of mineralogical material from Tsumeb, including specimens from public and private collections around the world.
Each specimen has a story to tell, and our criteria for specimen inclusion are diverse, but rigorous.
A specimen might be an example of a very rare mineral; it might be included because it is part of an uncommon paragenesis, or perhaps because the habit of one of the minerals is unusual. Specimens with a credible record of exactly where in the mine they were found are favoured, while others might have an interesting history of ownership (or provenance). Some specimens are included for purely aesthetic reasons!
Care has been taken to ensure that included images are exclusively of minerals which have been correctly identified. For this reason, many specimen descriptions are accompanied by analytical data or, at the very least, by details of how and where the analysis was conducted. Any uncertainly about mineral identifications is clearly noted in the descriptive text.
There are many (!) gaps in the TMN database but they will steadily reduce and, if you believe that you have specimens that could help us to fill any of them, please feel free to contact us.
— Malcolm Southwood, Raquel Alonso-Perez, Katie Sanders, Frank Keutsch