Distinct Mineral Species Research Articles

Arsenohauchecornite and tellurohauchecornite: new minerals in the hauchecornite group

SummaryArsenohauchecornite, Ni9BiAsS8, and tellurohauchecornite, Ni9BiTeS8 from the Sudbury area, Ontario, are now recognized as distinct mineral species in the Hauchecornite Group and not as varieties as described previously. Descriptions of these two minerals are given, summarized from Gait and Harris (1972).

The occurrence of vanadium, chromium, and other unusual elements in certain coals

AbstractIt has been found that the ashes of certain brands of vitrain interbedded with Coal Measure rocks in North Staffordshire and North Wales contain notable quantities of some of the less common elements, chiefly vanadium, chromium, titanium, and nickel. “ Cauldron “ vitrains from the Durham coalfield and Whitby jet show the same phenomenon, which appears to be fairly general for carbonaceous material of a black, brittle, lustrous type occurring in isolated bands or lumps in rocks. It is considered that current theories of the origin of rare elements ‐in coals cannot account satisfactorily for concentrations such as arc now reported. In addition, small but determinable quantities of copper, boron, lead, germanium and strontium have been found in certain coal scams; these occurrences were in some cases traced to the presence of distinct mineral species, such as copper pyrites and galena.

Clay minerals and bauxitic minerals. A review and classification based on a statistical method

SummaryA statistical study of clay and bauxitic minerals, which consisted of plotting all available analyses of these minerals on two triangular diagrams (figs. 1 and 7) and constructing frequency curves for the cardinal ratios, led to a classification of these minerals on a purely chemical basis. The suggestion is also made that among substances claimed to be minerals we can select only a few as belonging to definite mineral species, and that the others are probably mixtures of these selected minerals, or their hydration products, or colloidal hydrates of variable composition. The distinct crystalline mineral species thus singled out are as follows :Besides these minerals, other substances, such as termierite, anauxite, allophane, &c., are suggested as probable species, without, however, any clear statistical evidence. The bentonitic minerals, not belonging strictly to the pure hydrous aluminium silicates, are placed in a separate group.In conclusion, I should like to thank Dr. G. Hickling and Mr. G. S. Mockler for reading the MS. of this paper and for their valuable suggestions.

A New Occurrence of Cristobalite in California

Cristobalite, one of the rarer high-temperature forms of silica, was first described from the andesite of Cerro San Cristobal, near Pachuca, Mexico, by vom Rath,' and was established as a distinct mineral species by Mallard.2 Artificial cristobalite has been prepared in the Geophysical Laboratory at Washington and its properties and its relation to the other forms of silica have been studied by Fenner.3 Silica bricks are made up of artificial cristobalite and tridymite, and so these minerals are of some importance to the

Note on ‘Feather-ore’ : identity of ‘Domingite’ (=‘Warrenite’) with Jamesonite

The formula 2PbS. Sb2S3, given for jamesonite in all the textbooks, does not belong to jamesonite at all, but to the ‘Federerz’ (‘feather-ore’) from Wolfsherg in the Harz analysed by H. Rose in 1829, and for which the mineralogical names wolfsberglte (Huot, 1841) and plumosite (Haidinger, 1845) have been proposed. Rose's formula for the cleavable jamesonite from Cornwall was 3PbS. 2Sb2S3. In 1860 Rammelsberg united these, together with heteromorphite, under the name jamesonite and with the formula 2PbS. Sb2S3 a : this has since been followed in the textbooks, but, as will be pointed out below, it is very probable that there are here three distinct mineral species.

XVII. On Brochantite and its associations

The large series of combinations of copper with sulphuric acid found in mineral veins, present many features which call for attentive study.Some of the series, as Chalcanthite and Pisanite, are easily soluble in water, while others, as Brochantite and the members of the group allied to it, are insoluble therein, and the solubility seems to run in parallel lines with the percentage of copper.The “Basic ” sulphates have of late received considerable notice, and English mineralogists must remember with pleasure that the masterly essay by Prof. Maskelyne “On the minerals of the Brochantite group,” gave us for the first time a clear insight into the characters of some of its constituents. This elaborate, paper shewed that the ortho-rhombic varieties were clearly entitled to be divided into distinct mineral species.