The Piquiri Syenite Massif, southernmost Brazil, is part of the post-collisional magmatism related to the Neoproterozoic Brasiliano-Pan-African Orogenic Cycle. The massif is about 12 km in diameter and is composed of syenites, granites, monzonitic rocks and lamprophyres. Diopside-phlogopite, diopside-biotite-augite-calcic-amphibole, are the main ferro-magnesian paragenesis in the syenitic rocks...

REE (LREE) into the glass with respect to clinopyroxene, but the A group of chrome-spinel peridotite upper-mantle xenoliths from the reverse for Sr and Y, in both mica-bearing and mica-free parageneses. Lashaine volcano, northern Tanzania, differs from other xenoliths In a mica-bearing melt pocket, Rb and Ba partition preferentially at this locality in containing glassy melt pockets. Modal, min...

Bonding models for silicates are assessed in relation to the local environment of oxygen, as determined by analysis of the oxygen17 nuclear quadrupole coupling constants (NQCC), using Townes-Dailey methods. The experimental NQCC of the silica polymorph low cristobalite is indicative of covalent charge transfer from the oxygen lone pairs to silicon and is consistent with Pauling’s (d-p) a-bondin...

A metamorphosed olivine-rich aggregate was found in the least metamorphosed CV3 Y-86009. Although such aggregates were observed in CV3 Mokoia and Vigarano, and CO (CM) Acfer 094 [1-3], their precursors and formation mechanism have not been fully understood. Here, we report mineralogical observations of an olivine-rich aggregate in the Y-86009. The olivine-rich aggregate is embedded in matrix. I...

A synergetic effect between carbon nanotubes (CNTs) and graphene on diopside (Di) scaffolds was demonstrated. 3D network architecture in the matrix was formed through the 1D CNTs inlaid among the 2D graphene platelets (GNPs). The mechanical properties of the CNTs/GNPs/Di scaffolds were significantly improved compared with the CNTs/Di scaffolds and GNPs/Di scaffolds. In addition, the scaffolds e...

Ca-Mg silicates are receiving a growing interest in the field of bioceramics. In a previous study, wollastonite-diopside (WD) glass-ceramics were successfully prepared by a new processing route, consisting of the heat treatment of a silicone resin embedding reactive oxide particles and a Ca/Mg-rich glass. The in vitro degradation, bioactivity, and cell response of these new WD glass-ceramics, f...

Textural, major element and trace element data for xeno-liths from Salt Lake Crater, Hawaii indicate that typical four phase lherzolite inclusions (olivine, orthopyroxene, chrome diopside and spinel) found worldwide in basalts are not samples of primitive upper mantle. Rather, lherzolite may be the recrystallized residue left after a basaltic melt extracts the easily fused components from pre-e...

Introduction. The Wark-Lovering rims [1] found on many refractory inclusions are important recorders of nebular environments to which refractory inclusions were exposed after their formation, such as different temperature regimes and isotopic reservoirs [2]. As part of a large-scale survey of W-L rims to enable us to better understand the range of environments reflected in rims, an inclusion of...

Lapis lazuli is defined as a rock of varying composition. The following minerals have been identified in this rock by X-ray diffraction: lazurite, haüyne, sodalite, nosean, mica, diopside, wollastonite, calcite and pyrite. Among them the first two minerals, lazurite and haüyne, are responsible for the unique blue colour of massive lapis lazuli [1]. As it has been proved [2], the blue colour of ...

Single-crystal neutron-diffraction data, collected at 10 K on a natural sample of diopside, provided a structure that refined to R = 4.5% for 415 independent reflections. The structure refinement showed significant reduction of the M(2)–O(3C2),(3D2) bond lengths, resulting in a more regular M(2) polyhedron than at higher temperatures. A significant zero-point contribution to the atomic displace...