Review of Handbook of Mineralogy. II. Silica, Silicates.

From the Mineralogical Magazine (1995) 59, 771.

By R. A. Howie, Book Reviews Editor

This second volume in the proposed five-volume series is bound in two parts, each of 460 pages, and gives critical data on 904 silicates and silica minerals, all the silicate mineral species known and described as of 31 August, 1994. As in the previous volume on Elements, Sulfides, Sulfosalts (Mineral. Mag., 55, 146.) each species is given a one-page description, which includes the name and idealized chemical formula, crystal system, point group, habit, twinning, cleavage, fracture, tenacity, hardness (both Mohs and VHN) and density. The optical properties listed include colour, lustre, optic sign, refractive indices, pleochroism, etc., and the unit cell data given are the space group, cell dimensions, cell contents and the seven strongest lines of the XRD powder pattern. Up to three chemical analyses are quoted, together with empirical formulae and polytypes, and there is a brief statement on the type of geological occurrence, associated minerals and a few prominent localities. Finally the source of the name and up to eight references are listed.

This work is thus an extremely comprehensive data source. The authors plan a complete coverage of the mineral kingdom in five volumes, and this compilation on the silicates alone represents an immense project. At first glance, a reader may be surprised at the one-species-to-a-page approach: e.g. on facing pages we get orthoclase and orthoericssonite, or phlogopite and phosinaite, i.e. the common silicates get no more and no less coverage than relatively rare species. This is not a text to read, but rather an extremely valuable compilation of the fundamental data and sufficient references to allow further investigation. With the number of species covered, division into two separately bound parts was clearly sensible, but having checked on a particular species one is always finding that the related species one wants to look up is in the other part.

My one serious criticism is that there is no index. At first sight, since the work is arranged alphabetically from abswurmsbachite to zussmanite, this might not seem necessary but one needs to know that it is no good looking for tourmaline or garnet – one must look up the individual species such as elbaite or grossular, although hydrogrossular is mentioned only under hibschite, and while schorlomite has an entry melanite does not. It seems a pity that melilite is not covered, åkermanite and gehlenite being dealt with, but not the commoner intermediate member of the series.

In this format, there is, of course, no room for diagrams or illustrations, but as an auxiliary aid a diagrammatic classification of the amphiboles is included at the beginning of part 1, in an attempt to clarify the ‘labyrinthine’ nomenclature of this complex group.