In general, δZn values of various rocks and minerals do not appear to significantly vary. The δZn value of bulk silicate Earth (BSE) is +0.28 + 0.05‰. Fractionation of Zn isotopes by igneous processes is generally insignificant, and δZn values of basalt fall within the range of +0.2 to +0.3‰, encompassing the value for BSE. δZn values of clay minerals from diverse environments and of diverse ages have been found to fall within the same range as basalts, suggesting negligible fractionation between the basaltic precursors and sedimentary materials. Carbonates appear to be more Zn-enriched than other sedimentary and igneous rocks. For example, the δZn value of a limestone core taken from the Central Pacific was +0.6‰ at the surface and increased to +1.2‰ with depth The Zn isotopic compositions of various ores are not well-characterized, but smithsonites and sphalerites (Zn carbonates and Zn sulfides, respectively) collected from various localities in Europe had δZn values ranging from -0.06 to +0.69‰, with smithsonite potentially slightly heavier by 0.3‰ than sphalerite.