The application of Raman spectroscopy to djerfisherite identification

Abstract

Raman spectra were acquired from the synthetic cubic K6Fe25S26Cl phase (55.3 wt% Fe) and ten natural djerfisherites K6(Fe,Cu,Ni)25S26Cl with various contents of Fe (from 15.5 to 22.6 atoms per formula unit (apfu)) and Ni + Cu + Co (from 1.4 to 9.0 apfu). The natural samples came from rocks of the Udachnaya, Obnazhennaya and Vtorogodnitsa kimberlite pipes and high‐grade contact marbles near Kochumdek River (Siberian craton, Russia). Diagnostic features of both synthetic and natural djerfisherite Raman spectra can be summarized as follows: the presence of two strong bands at 264–273 and 321–344 cm−1 and from two to five medium/weak bands in the region from 90 to 190 cm−1. Raman spectra of Fe‐rich ((Ni + Cu + Co) < 2.4 apfu) djerfisherite have up to nine bands, whereas the number of Raman bands in spectra of djerfisherite with high impurity concentration ((Ni + Cu + Co) = 8.7–9 apfu) reduces to four. The Raman spectra of djerfisherite enriched in impurities ((Ni + Cu + Co) = 5–9 apfu) are also characterized by broadening and asymmetry of bands in comparison with Ni + Cu + Co‐poor djerfisherite. Experimental Raman spectra of synthetic and natural djerfisherites show good agreement with theoretical spectra calculated using lattice‐dynamical software. The group of bands in the range 90–190 cm−1 is associated with the S–Fe–S bending vibrations in FeS4 tetrahedra and FeS6 octahedra. The band group in the range of 260–350 cm−1 is due to the Fe–S stretching vibrations in both polyhedra. Copyright © 2017 John Wiley & Sons, Ltd.

A Plethora of Epigenetic Minerals Reveals a Multistage Metasomatic Overprint of a Mantle Orthopyroxenite from the Udachnaya Kimberlite

“…Djerfisherite is a common mineral crystallizing during late stages of kimberlite melt evolution; it has also been identified in kimberlite-borne xenoliths (see review in [58]). In particular, djerfisherite was repeatedly found in the Udachnaya-East pipe among the groundmass minerals of various units of kimberlites [12,[77][78][79] and as a daughter mineral inside primary and secondary melt inclusions in the groundmass kimberlite minerals [13,[80][81][82]. It also occurs in the intergranular space of various mantle xenoliths [15,16] and as a daughter mineral inside the secondary melt inclusions in olivine from sheared peridotite xenoliths [16,20,22].…”

Can primitive kimberlite melts be alkali‐carbonate liquids: Composition of the melt snapshots preserved in deepest mantle xenoliths

“…[20,70,72,73] Detailed studies of the chemical and mineralogical compositions of these unaltered kimberlites can be found elsewhere. [13][14][15]17,18,[72][73][74][75][76][77][78] These kimberlites also contain various types of unserpentinised mantle xenoliths [66][67][68][79][80][81] The studied sheared peridotite xenoliths are defined by the presence of large porphyroclasts (1-10 mm) of olivine, garnet, and pyroxene, which are set in a matrix consisting of very fine-grained neoblasts (0.1-0.5 mm) of mostly olivine and lesser pyroxene (Figures 1b and 2). According to textural classifications, [82,83] the studied samples have porphyroclastic, mosaic-porphyroclastic, and fluidal-mosaic-porphyroclastic textures (Figures 1b and 2 and Table 1).…”

Sulfides in the marbles of spurrite-merwinite facies: the Kochumdek River, East Siberia

“…На этом этапе возникли магнетитовые каймыобрастания вокруг сульфидов, а позднее произошло замещение пирротина и расвумита джерфишеритом, устойчивом в узком поле низкой активности S 2и высокой калия [15]. Поскольку в габброидах из кровли траппа присутствуют хлорсодержащие амфибол, биотит, апатит и хлорит [5], в качестве наиболее вероятного источника хлора для образования джерфишерита следует рассматривать поздние дифференциаты базальтовой магмы [13].…”