Emeralds from Colombia are among the most highly-prized and valuable gemstones. Their growth phenomena including information about the geology of the area were described in detail by Pig-natelli et al. (2015, 2022) and Schmetzer and Martayan (2023). Here, we present data obtained by scanning electron microscopy (SEM), electron microprobe analysis (EMPA), and infrared absorption spectroscopy (IR) for five emerald crystals. The surface of the crystals shows both, growth phe-nomena as well as dissolution phenomena, the latter as etch pits (EP). Such EP have been used previously for other beryl types, mainly from pegmatitic environments (Kurumathoor and Franz, 2018); the Colombian emeralds come from low-grade metamorphosed black shales and thus offer the possibility to extend the use of EP as a provenance indicator to other types of beryl deposits. Internal structures are manifested in chemical zoning, investigated by EMPA and micro-X-ray fluo-rescence (µXRF). The crystals are characterized chemically by EMPA, polarized IR spectroscopy of oriented crystals showed the presence of fluids in the channels of the beryl structure.
This data set was collected in the frame of the ICDP drilling project DIVE (Drilling the Ivrea-Verbano ZonE) to determine the thermal properties of lower crustal lithologies and their variabilities. Two boreholes were drilled, the first 5071_1_B (in Ornavasso, final depth: 578.5 m) intersects the amphibolite-facies metasedimentary succession of the Ivrea-Verbano Zone, and the second borehole 5071_1_A (in Megolo, final depth: 909.5 m) is located within the mafic complex.
Thermal properties were measured on fresh drill cores from the two DIVE boreholes and surface samples collected from nearby outcrops. The data set comprises thermal conductivity (TC), thermal diffusivity (TD), and specific heat capacity (Cp) measurements as well as measurements on concentrations of heat producing elements (HPE) Uranium (U), Thorium (Th), and Potassium (K) and the calculated radiogenic heat production (A).