The crystal-chemical literature and the present state of scientific information on crystal chemistry

1981 ◽  
Vol 21 (5) ◽  
pp. 683-702 ◽  
Author(s):  
�. A. Gilinskaya
Keyword(s):  
Crystal Chemistry ◽  
Present State ◽  
Scientific Information ◽  
Crystal Chemical

Crystal chemistry of ettringite

1962 ◽  
Vol 33 (256) ◽  
pp. 59-64 ◽  
Author(s):  
Duncan McConnell ◽  
Joseph Murdoch
Keyword(s):  
Crystal Chemistry ◽  
Simple Form ◽  
Unit Cell ◽  
Crystal Chemical ◽  
Aluminium Sulphate ◽  
Hexagonal Unit Cell ◽  
Cell Dimensions ◽  
Unit Cell Dimensions ◽  
Anionic Groups ◽  
Oxygen Atoms

Summary Crystal-chemical calculations are based on three chemically analysed samples of ettringite and their respective unit-cell dimensions and specific gravities. The large hexagonal unit cell is deduced to contain 384 oxygen atoms, 64 cations with co-ordination number 6 or more, and 48 cations with co-ordination number 4 or less. Some substitution of cations with co-ordination number 3 apparently takes place, and any excess above 192 H2O takes place in the form of substitution of (H4O4) for XO4 anionic groups. The isomorphism is extremely complex but can be generalized in simple form as 16[A4(XO4)3(H2O)12], where A represents atoms with six-fold co-ordination (Ca, Na, Al) and X represents atoms with four-fold coordination (S, Si, H4, and possibly some of the Al). It is implied that an isostructural series of silicon-containing calcium aluminium sulphate hydrates might exist, the extreme compositions of which are: 6CaO.Al2O3.3SO3.3SiO2.24H2O and 6CaO.Al2O3.3SO3.30H2O.

A review of crystal chemistry of natural silicates of alkaline elements in the light of new structural data

2014 ◽  
Vol 78 (2) ◽  
pp. 253-265 ◽  
Author(s):  
N. V. Zubkova ◽  
I. V. Pekov ◽  
D. Yu. Pushcharovsky
Keyword(s):  
Crystal Structures ◽  
Crystal Chemistry ◽  
Structural Data ◽  
Crystal Chemical ◽  
Chemical Feature ◽  
New Members ◽  
Silanol Groups ◽  
Crystal Chemical Feature

AbstractA review is presented here of the crystal chemistry of natural silicates of alkaline elements, mainly Na, with a focus on reporting recent data on the structural mineralogy of the new members of this chemical family and their crystal structures. The majority of the natural hydrous silicates of alkaline elements studied are characterized by a specific crystal-chemical feature − the presence of silanol groups Si−OH. The discovery of the two new minerals, chesnokovite and yegorovite, means that all the main topological types of the [SixOy] complexes are represented in the crystal structures for this family.

CRYSTAL CHEMISTRY OF CANCRINITE-GROUP MINERALS WITH AN AB-TYPE FRAMEWORK: A REVIEW AND NEW DATA. II. IR SPECTROSCOPY AND ITS CRYSTAL-CHEMICAL IMPLICATIONS

2011 ◽  
Vol 49 (5) ◽  
pp. 1151-1164 ◽  
Author(s):  
N. V. Chukanov ◽  
I. V. Pekov ◽  
L. V. Olysych ◽  
N. V. Zubkova ◽  
M. F. Vigasina
Keyword(s):  
Ir Spectroscopy ◽  
Crystal Chemistry ◽  
Crystal Chemical

Crystal chemical formula for sartorite homologues

2015 ◽  
Vol 79 (1) ◽  
pp. 25-31 ◽  
Author(s):  
Emil Makovicky ◽  
Dan Topa
Keyword(s):  
Crystal Chemistry ◽  
Homologous Series ◽  
Crystal Chemical ◽  
Chemical Formula ◽  
Crystal Chemical Formula ◽  
Systematic Classification

AbstractThe members of the sartorite homologous series are complex sulfides Me2+8N–16–2XMe3+16+XMe+XS8N+8 where Me2+ is Pb and Me3+ is As and Sb, whereas Me+ is Ag and/or Tl. This paper presents calculation formulae for the homologue order N and for the separate substitution percentages for Tl + (As,Sb) ↔ 2Pb and Ag + (As,Sb) ↔ 2Pb substitutions. This enables one to evaluate the crystal chemistry and build a systematic classification of the sartorite homologues.

Crystal chemistry and intracrystalline relationships of orthopyroxene in a suite of high pressure ultramafic nodules from the ‘Newer Volcanics’ of Victoria, Australia

1994 ◽  
Vol 58 (391) ◽  
pp. 325-332 ◽  
Author(s):  
Gianmario Molin ◽  
Marilena Stimpfl
Keyword(s):  
High Pressure ◽  
Melting Point ◽  
Crystal Chemistry ◽  
Site Occupancy ◽  
Mantle Melting ◽  
Cation Substitution ◽  
Crystal Chemical ◽  
Formula Unit

AbstractA suite of orthopyroxenes from spinel Iherzolite xenoliths associated with basanites occurring in the Victorian (Australia) post-Pliocene ‘Newer Volcanics’ province was investigated by means of a crystal chemical methodology which provides accurate site occupancy and site configuration parameters.The M1 configuration is essentially constrained by AlVI rather than Fe2+. In addition, Fe3+, Cr3+ and Ti4+ are confined to M1 (Molin, 1989) and AlIV to TB. M2 is controlled by FeM22+ ⇌ MgM2, constrained by (Fe2+ + Ca)M2 > 0.14 atoms per formula unit (p.f.u.). Cation substitution in TB and M2 constrains the sum of the volumes of the respective polyhedra VTB+VM2 to remain essentially constant. Therefore, M2 favours the retention of the large Fe2+ up to melting-point, causing non-ideality of this iron-depleted orthopyroxene. As a consequence, the investigated orthopyroxene can be considered an ultimate Fe2+ carrier during partial mantle melting.

The role of beryllium in alloys, Zintl phases and intermetallic compounds

2020 ◽  
Vol 75 (5) ◽  
pp. 421-439 ◽  
Author(s):  
Oliver Janka ◽  
Rainer Pöttgen
Keyword(s):  
Phase Diagrams ◽  
Intermetallic Compounds ◽  
Crystal Chemistry ◽  
Physical Property ◽  
Present Review ◽  
Light Weight ◽  
Crystal Chemical ◽  
Zintl Phases ◽  
Crystal Chemical Data

AbstractAlthough beryllium is widely used as alloying component in diverse light-weight alloys, the crystal chemistry of beryllium containing Zintl phases and intermetallic compounds is only scarcely developed and only few phase diagrams, mostly the industrially relevant ones, have been studied in detail. The present review summarizes the crystal chemical data of binary and ternary beryllium intermetallic compounds along with the results of the few documented physical property studies.

Copper minerals from volcanic exhalations – a unique family of natural compounds: crystal-chemical review

2018 ◽  
Vol 74 (6) ◽  
pp. 502-518 ◽  
Author(s):  
Igor V. Pekov ◽  
Natalia V. Zubkova ◽  
Dmitry Yu. Pushcharovsky
Keyword(s):  
High Temperature ◽  
Crystal Chemistry ◽  
Chemical Characterization ◽  
Crystal Chemical ◽  
Alkali Cations ◽  
Genetic Groups ◽  
Copper Mineralization ◽  
Group I ◽  
Group Ii

The crystal-chemical characterization of oxysalts (sulfates, arsenates, vanadates, selenites, silicates, molybdates and borates), chlorides and oxides with species-defining Cu2+ formed in volcanic fumaroles (96 minerals representing 80 structure types; 81 species are endemic to fumarolic formation) is given. Copper minerals are known only from oxidizing-type fumaroles. The most diverse copper mineralization occurs at the Tolbachik volcano (Kamchatka, Russia). Copper minerals from fumarolic systems are subdivided into two genetic groups: Group I are minerals formed in the hot zones of fumaroles (>473 K, mainly 673–973 K) and Group II are minerals formed in the moderately hot zones of fumaroles (<473 K, mainly at 343–423 K). Group I includes 81 mineral species. Their most defining chemical feature is that all of them are hydrogen-free, and many of them contain the additional anion O2−. In comparison with minerals from other geological environments, in minerals of Group I the Cu2+ cation exhibits the strongest affinity for four- and fivefold coordinations and the strongest distortion of Cu2+-centred octahedra. Group II consists of 15 chlorides and sulfates including 13 H-bearing species. In these minerals the Cu2+ cation shows affinity for octahedral coordination, with OH− and/or H2O0 as ligands. In terms of crystal chemistry these minerals are closer to supergene minerals rather than to high-temperature fumarolic species. Temperature is the major factor governing the crystal chemistry of Cu2+ oxysalts and chlorides in low-pressure systems. The defining feature of fumarolic copper mineralization over this whole temperature range is the important role of alkali cations. The available data on complexes of Cu2+-centred polyhedra in the structures of natural oxysalts and halides are summarized and reviewed. Isomorphism in copper minerals from volcanic exhalations is discussed. The structures of high-temperature Cu oxysalts with additional O2− anions (i.e. O atoms non-bonded to S6+, Mo6+, As5+, V5+, Se4+ or B3+) are also interpreted using an approach based on oxocentred tetrahedra.

scholarly journals Asbecasite: crystal structure refinement and crystal chemistry

1993 ◽  
Vol 57 (387) ◽  
pp. 315-322 ◽  
Author(s):  
Michele Sacerdoti ◽  
Gian Carlo Parodi ◽  
Annibale Mottana ◽  
Adriana Maras ◽  
Giancarlo Della Ventura
Keyword(s):  
Crystal Structure ◽  
Crystal Chemistry ◽  
Structure Determination ◽  
Electron Microprobe ◽  
Structure Refinement ◽  
Volcanic Complex ◽  
Crystal Chemical ◽  
Crystal Structure Refinement ◽  
Roman Potassic Province ◽  
Original Crystal

AbstractThe crystal structure of antimonian asbecasite in an ejectum of hypabyssal origin occurring at Tre Croci near Vetralla, Vico volcanic complex, Roman potassic province, Latium, Italy, has been refined to R = 0.042, and is compared to the original crystal structure determination carried out on the Sb-free asbecasite of hydrothermal metamorphic origin from the type-locality, Cherbandung in Binna valley, Monte Leone nappe, Switzerland. New electron microprobe analyses of samples from both localities demonstrate crystal-chemical features that permit distinction between asbecasites from the two occurrences, so far the only known localities for this mineral.

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