TY - JOUR

T1 - Spectroscopic constraints on growth of Siberian mixed-habit diamonds

AU - Skuzovatov, Sergei Yu

AU - Zedgenizov, Dmitry A.

AU - Rakevich, Alexander L.

N1 - Publisher Copyright: © 2017, Springer-Verlag Berlin Heidelberg.

PY - 2017/6/1

Y1 - 2017/6/1

N2 - Notable within-crystal variability of mineralogical and geochemical properties of single natural diamonds are commonly attributed to changing chemistry of parental fluids, sources of carbon and redox conditions of diamond precipitation. A distinct type of compositional heterogeneity (mixed-habit structure) is well-known to occur in diamonds as well as in many other minerals due to purely “structural” reasons that are unequal crystal chemistry of crystallographically different faces and selective absorption and fractionation of impurities between adjacent growth pyramids. Based on the combined cathodoluminescence, Fourier-transformed infrared spectroscopy and photoluminescence spectroscopy, study of nine diamond crystals with different growth histories and external morphology, but all showing mixed-habit patterns at different growth stages, we show that mixed-diamonds may grow in closed system conditions or with a slowly decreasing growth rate from a media with a much lower impurity content than previously thought. Intracrystal nitrogen distribution seems to be a function of growth rate even in the cases of unusual impurity partitioning between growth sectors. Generally poor with IR-active hydrogen at moderate nitrogen aggregation parameters, studied diamonds likely resemble the low hydrogen content from the growth medium that, for cubic diamonds, was typically suggested hydrogen-rich and a crucial factor for growth of cubic and mixed-habit diamonds. We also show that mixed-habit diamond growth may occur not only in peridotitic suite but also in an extended field of geochemical affinities from high-Ni to low-Ni or maybe even Ni-free environments, such as pyroxenitic or eclogitic.

AB - Notable within-crystal variability of mineralogical and geochemical properties of single natural diamonds are commonly attributed to changing chemistry of parental fluids, sources of carbon and redox conditions of diamond precipitation. A distinct type of compositional heterogeneity (mixed-habit structure) is well-known to occur in diamonds as well as in many other minerals due to purely “structural” reasons that are unequal crystal chemistry of crystallographically different faces and selective absorption and fractionation of impurities between adjacent growth pyramids. Based on the combined cathodoluminescence, Fourier-transformed infrared spectroscopy and photoluminescence spectroscopy, study of nine diamond crystals with different growth histories and external morphology, but all showing mixed-habit patterns at different growth stages, we show that mixed-diamonds may grow in closed system conditions or with a slowly decreasing growth rate from a media with a much lower impurity content than previously thought. Intracrystal nitrogen distribution seems to be a function of growth rate even in the cases of unusual impurity partitioning between growth sectors. Generally poor with IR-active hydrogen at moderate nitrogen aggregation parameters, studied diamonds likely resemble the low hydrogen content from the growth medium that, for cubic diamonds, was typically suggested hydrogen-rich and a crucial factor for growth of cubic and mixed-habit diamonds. We also show that mixed-habit diamond growth may occur not only in peridotitic suite but also in an extended field of geochemical affinities from high-Ni to low-Ni or maybe even Ni-free environments, such as pyroxenitic or eclogitic.

KW - Diamond

KW - Hydrogen

KW - Infrared absorption

KW - Mixed-habit growth

KW - Nitrogen

KW - Photoluminescence

KW - Siberian craton

KW - INTERNAL STRUCTURE

KW - INFRARED-ABSORPTION

KW - OPTICAL-CENTERS

KW - MIR KIMBERLITE

KW - NATURAL DIAMONDS

KW - STABLE-ISOTOPES

KW - CLOUDY MICROINCLUSIONS

KW - CRYSTAL-GROWTH

KW - SYNTHETIC DIAMOND

KW - NITROGEN IMPURITY

UR - http://www.scopus.com/inward/record.url?scp=85019664176&partnerID=8YFLogxK

U2 - 10.1007/s00410-017-1366-9

DO - 10.1007/s00410-017-1366-9

M3 - Article

AN - SCOPUS:85019664176

VL - 172

JO - Contributions to Mineralogy and Petrology

JF - Contributions to Mineralogy and Petrology

SN - 0010-7999

IS - 6

M1 - 46

ER -