Five smithsonite samples from locations in Germany, Mexico and Namibia have been investigated with cathodoluminescence (CL) spectroscopy and trace-element analyses. As with other carbonates, the CL properties of smithsonite are mainly controlled by Mn2+- and Fe2+-incorporation, because these elements are the most important activator and quencher species, respectively. Additional trace elements may have either a quenching effect (Cu) or have only small or no influence (Ca, Pb). A linear correlation exists between the Mn content and the intensity of the Mn-emission band in smithsonite, which can be quantified, if the Cl intensity is related to the number of moles of Mn rather than the weight fraction. A correlation between the Cl intensity and the Mn concentration, which is valid for all trigonal carbonates, is obtained from the published results of calcite, dolomite and smithsonite. Matrix effects due to the different chemical composition of the carbonate minerals seem to be of lesser importance.

The introduction of a fifth amphibole group, the Na-Ca-Mg-Fe-Mn-Li group, defined by 0.50 < B(Mg,Fe2+,Mn2+,Li) < 1.50 and 0.50 ≤ B(Ca,Na) ≤ 1.50 a.f.p.u. (atoms per formula unit), with members whittakerite and ottoliniite, has been required by recent discoveries of B(LiNa) amphiboles. This, and other new discoveries, such as sodicpedrizite (which, here, is changed slightly, but significantly, from the original idealized formula), necessitate amendments to the IMA 1997 definitions of the Mg-Fe-Mn-Li, calcic, sodic-calcic and sodic groups. The discovery of obertiite and the finding of an incompatibility in the IMA 1997 subdivision of the sodic group, requires further amendments within the sodic group. All these changes, which have IMA approval, are summarized.