Mineral portrait garnet (english abstract)

This portrait mainly deals with the 6 classic garnets, their amazing history, the world’s best known classic and modern localities and deposits and their use as a gems or abrasives. It also deals with the common belief related to the non-existence of blue garnets and its refutation proven by new finds. A separate chapter deals with synthetic garnets. But it also deals with the mix up of definitions, groupings and old and unnecessary terms, which have finally been terminated or brought to a common denominator.

In 2012 the IMA (CNMNC) has defined garnets as members of the Garnet Supergroup, which include all minerals isostructural with garnet regardless of what elements occupy the four atomic sites; i.e. the supergroup includes several chemical classes . Those minerals are closely related to each other and may form a series with each other. Some garnets form intermediary minerals between each member, and may even be intergrown within a single crystal.

With the publication of the new nomenclature of the garnet supergroup, the term “garnet group” does not have its meaning anymore and the intermediate working term “Garnet superstructural group” has been replaced by “Garnet Supergroup”.
There are 32 approved species and 5 “candidate” species waiting on approval. The 32 species are subdivided by their Z-charge into 29 species, which belong to 5 groups and to 3 single representative species.
One of those 5 groups is the “Garnet group”, consisting of the 6 former (classic) garnets Pyrope, Grossular, Spessartine, Almandine, Uvarovite and Andradite plus 8 rarer garnets , as Menzerite-(Y), Eringaite, Goldmanite, Momoiite, Knorringite, Calderite, Majorite and Morimotoite.