..., 92°18′E), Tibet, China, with wenjiite, Ti 10 (Si,P,□) 7 , Al-rich spinel, osbornite, TiN, a Ca-amphibole particularly enriched in Ti, a Sr-rich dmisteinbergite, CaAl 2 Si 2 O 8 , and amorphous phases (probably residual melt) (holotype and first cotype), and (2) as several grains with corundum...

...Aaron S. Bell; Laura E. Waters; Mark Ghiorso Abstract The compositions of cotectic olivine-spinel pairs in mafic magmas provide information on the oxygen fugacity of their host liquid, which can be accessed with a thermodynamic analysis of the olivine-spinel-liquid peritectic reaction: 3 Fe 2 SiO 4...

... the measured compositional profiles and the crystallographic axis orientations were calculated (Part 4 of the Online Materials 1 ). The crystallization temperatures of olivine cores were estimated by the Al-in-olivine thermometer ( Coogan et al. 2014 ) using chemical compositions of Cr-spinel...

... = orthopyroxene; Ol = olivine; S = spinel. ( a ) Sample GN9912 with multigrain aggregates of amphibole that often surround spinel. The rectangle labeled B is equivalent to the photomicrograph in the lower righthand corner of this image. ( b ) A photomicrograph of sample GN9912 from the box labeled “B” on image...

...-crystal X-ray diffraction. The studied tourmaline occurs as transparent dark blue crystals (with equant external morphology) up to 3 mm in size and forms veinlets cutting a (Mg,Al)-rich metamorphosed mafic-ultramafic rock (Mg >> Fe) composed of spinel, pargasite, clinochlore, phlogopite...

... excitation, image width = 0.75 mm. Green luminescence in gems is not uncommon; it can be caused by a range of defects such as Mn 2+ in a tetrahedral site found in genthelvite, willemite ( Czaja et al. 2021 ), and spinel ( Rodríguez-Mendoza et al. 1995 ), or H3 and H4 nitrogen vacancy defects...

... of olivine, orthopyroxene, clinopyroxene, plagioclase, spinel-group minerals, calcic amphiboles, apatite, micas, and pentlandite, among other species. We find (1) examples of monomineralic inclusions of clinopyroxene and plagioclase trapped in a globule of oxide melt, (2) evidence of the possible existence...

... the shank-angle reconstruction mode because of the poly-phased nature of our region of interest ( Fougerouse et al. 2021c ). The sample comprises dry residual layers of porhyroblastic garnet-cordierite-spinel-sapphirine-osumilite (now replaced by symplectites of K-feldspar-cordierite-dendritic...

...Emanuela Gennaro; Gianluca Iezzi; Manuela Nazzari; Francesco Vetere; Piergiorgio Scarlato; Letizia Giuliani; Georg F. Zellmer Abstract The crystal-chemical variations of spinels grown as a function of cooling rate (Δ T /Δ t ) were analyzed via X-ray electron-microprobe (EPMA) maps. Maps were...

...L.Z. Reznitsky; E.V. Sklyarov; I.G. Barash Abstract —The paper presents data on two groups of magnesian Cr–V spinel occurring as rock-forming minerals in various types of Cr–V bearing rocks of the Sludyanka metamorphic complex (South Baikal area, Siberia, Russia): (i) low-Al magnesiochromite...

... that cannot be quantified solely from thin sections: spinel layering, distribution of silicic glass, and related vesicles. Moreover, high-density volumes identified as sulfides were detected in two xenoliths, showing no relation with the spinel layering in one case and a preferential concentration along...

... and impregnated types. Residual peridotites resulted from early depletion and later refertilization processes, whereas impregnated peridotites developed due to episodic melt impregnations within and across the mantle. Mg#s and NiO contents, spinel Cr#, Mg#, and TiO 2 in olivines, Mg# and Al 2 O 3 contents...

... formed by post-melting boninite intrusion (Bénard et al., 2022); (2) these samples show different bulk-rock and spinel (Sp) compositions compared to residual SSZ peridotites. The above arguments are fully consistent with and, indeed, reinforce our viewpoint in Chen et al. (2023) that the Chagan-Uzun...

...Lan F. Xie; Hong Y. Chen; Bing K. Miao; Wen L. Song; Zhi P. Xia; Chuan T. Zhang; Guo Z. Chen; Jin Y. Zhang; Si Z. Zhao; Xu K. Gao Abstract Pink spinel anorthosite (PSA) and pink spinel troctolite (PST) are two lunar lithologies known to contain Mg-rich spinel. PSA rich in spinel and lacking mafic...

...Roberta L. Flemming; Song Gao; Candace N. Freckelton; Phil J.A. McCausland Abstract Spinel-group minerals are among the best-known and widely used minerals in diamond exploration due to their ubiquity, resistance to weathering, and utility as petrogenetic indicators. The kimberlite indicator...

... fine-grained ilmenite grains; the other occurs as an aggregate of ilmenite, rutile, spinel, and loveringite. We propose that the two types of micro-textures formed through subsolidus breakdown of armalcolite by different processes. The formation of ilmenite inclusions in armalcolite is related to slow...

... was then decreased to 1250 °C with a cooling rate between 4.2 and 0.8 °C/h. Then, the furnace was turned off and the experiment ended. The crystal-growth period was, therefore, between 52 and 275 h. Further details are given in the above publication. * E-mail: [email protected] . The oxide spinel...

... definition cuproiridsite cuprorhodsite ferrorhodsite malanite xingzhongite dayingite Hatert & Burke (2008) discussed spinel and thiospinel groups as follows: Under the leadership of the late Michael Fleischer, the Commission on New Minerals and Mineral Names (CNMMN...

...Hugh Rollinson; Jacob Adetunji Abstract We investigated the compositions of a suite of 361 chrome-bearing spinels from spinel peridotites, ophiolitic mantle chromitites and from layered igneous intrusions in which the Fe 2+ /Fe 3+ ratio has been determined by Mössbauer spectroscopy. We explore...

..., Eastern Sayans, Russia, have been analyzed and described. Detrital grains of Ir–Os alloy, considered to have been derived from the Lysanskiy layered ultrabasic complex, are interpreted to be domains of melt in the interstices of olivine–chromian spinel cumulates. This melt fractionated before...