ALBERT

Description: 〈span〉〈div〉Abstract〈/div〉The crystal structure of polylithionite-1〈span〉M〈/span〉 from Darai-Pioz, (K〈sub〉0.97〈/sub〉Na〈sub〉0.03〈/sub〉Rb〈sub〉0.01〈/sub〉)〈sub〉Σ1.01〈/sub〉(Li〈sub〉2.04〈/sub〉Al〈sub〉0.84〈/sub〉 Ti〈sup〉4+〈/sup〉〈sub〉0.09〈/sub〉Fe〈sup〉3+〈/sup〉〈sub〉0.03〈/sub〉)〈sub〉Σ3.00〈/sub〉(Si〈sub〉3.98〈/sub〉Al〈sub〉0.02〈/sub〉)O〈sub〉10〈/sub〉[F〈sub〉1.68〈/sub〉(OH)〈sub〉0.33〈/sub〉]〈sub〉Σ2〈/sub〉, 〈span〉a〈/span〉 5.1974(4), 〈span〉b〈/span〉 8.9753(6), 〈span〉c〈/span〉 10.0556(7) Å, β 100.454(1)°, 〈span〉V〈/span〉 461.30(6) Å〈sup〉3〈/sup〉, space group 〈span〉C〈/span〉2, 〈span〉Z〈/span〉 = 2, was refined to 〈span〉R〈/span〉〈sub〉1〈/sub〉 = 1.99% using Mo〈span〉K〈/span〉α X-radiation. In the space group 〈span〉C〈/span〉2, there are three octahedrally coordinated 〈span〉M〈/span〉 sites in the 1〈span〉M〈/span〉 mica structure: the 〈span〉M〈/span〉(1) site is occupied by Li〈sup〉+〈/sup〉 and minor vacancy that is likely locally associated with Ti〈sup〉4+〈/sup〉 at the 〈span〉M〈/span〉(2) site; the 〈span〉M〈/span〉(2) site is occupied dominantly by Al〈sup〉3+〈/sup〉, with other minor divalent to tetravalent cations; the 〈span〉M〈/span〉(3) site is completely occupied by Li〈sup〉+〈/sup〉. In the space group 〈span〉C〈/span〉2, the structure is completely ordered. Each non-bridging O〈sup〉2–〈/sup〉 ion is surrounded by an ordered arrangement of 2Li〈sup〉+〈/sup〉 + Al〈sup〉3+〈/sup〉 + Si〈sup〉4+〈/sup〉 with an incident bond-valence sum of 1.95 〈span〉vu〈/span〉 (valence units). The F〈sup〉–〈/sup〉 ion is coordinated by Li〈sup〉+〈/sup〉 + Li〈sup〉+〈/sup〉 + Al〈sup〉3+〈/sup〉 with an incident bond-valence sum of 0.84 〈span〉vu〈/span〉 (values around F〈sup〉–〈/sup〉 generally tend to be lower than ideal). Thus, the valence-sum rule is satisfied, both long range and short range. In the space group 〈span〉C〈/span〉2/〈span〉m〈/span〉, there is long-range order but not short-range order. There are three different short-range arrangements, one of which has bond-valence deficiencies of 0.38 and 0.49 〈span〉vu〈/span〉 around the non-bridging O〈sup〉2–〈/sup〉 ion and the F〈sup〉–〈/sup〉 ion, destabilizing the structure relative to the more ordered arrangement of the 〈span〉C〈/span〉2 structure, which conforms more closely to the valence-sum rule. The drive to lower the symmetry in polylithionite-1〈span〉M〈/span〉 from 〈span〉C〈/span〉2/〈span〉m〈/span〉 to 〈span〉C〈/span〉2 comes from the short-range bond-valence requirements of the structure.〈/span〉

Description: The crystal structure of schüllerite, ideally Na 2 Ba 2 Mg 2 Ti 2 (Si 2 O 7 ) 2 O 2 F 2 , a 5.396(1), b 7.071(1), c 10.226(2) Å, α 99.73(3), β 99.55(3), 90.09(3)°, V 379.1(2) Å 3 , Z = 1, from the Eifel volcanic region, Germany, has been refined in the space group P 1 to R = 1.33% using 2247 observed ( F o 〉 4 F ) reflections collected with a single-crystal Bruker D8 three-circle diffractometer equipped with a rotating-anode generator (Mo K α radiation), multilayer optics and an APEX-II detector. The empirical formula for schüllerite was calculated on the basis of 18 (O + F) anions: (Na 1.10 Ca 0.43 Mn 0.30 Fe 2+ 0.17 ) 2 (Ba 1.57 Sr 0.14 K 0.14 0.15 ) 2 (Mg 0.79 Fe 2+ 0.71 Na 0.33 Fe 3+ 0.17 ) 2 (Ti 1.67 Fe 3+ 0.21 Nb 0.09 Zr 0.02 Al 0.01 ) 2 Si 3.95 O 15.93 F 2.07 , D calc. = 3.879 g/cm 3 , Z = 1, with Fe 3+ / (Fe 2+ +Fe 3+ ) ratio determined by Mössbauer spectroscopy. Schüllerite is a Group-IV TS-block mineral: Ti + Mg = 4 apfu . The crystal structure of schüllerite is an alternation of TS (Titanium Silicate) and I (intermediate) blocks of the ideal composition [Na 2 Mg 2 Ti 2 (Si 2 O 7 ) 2 O 2 F 2 ] 4– and [Ba 2 ] 4+ , respectively. The TS block is composed of the central O (octahedral) sheet and two adjacent H (heteropolyhedral) sheets. In the O sheet, there are two brookite-like chains of M O octahedra of the following ideal compositions: [Mg 2 O 8 ] 12– [M O (1)] and [Na 2 O 8 ] 14– [M O (2)]; the ideal composition of the O sheet is [Na 2 Mg 2 O 2 F 2 ] 0. The H sheet is composed of the [5]-coordinated Ti-dominant M H polyhedra and Si 2 O 7 groups; the composition of the two H sheets is [Ti 2 (Si 2 O 7 ) 2 ] 4–. In schüllerite, the TS block has a topology characteristic of Group IV of TS-block minerals: two H sheets connect to the O sheet such that two Si 2 O 7 groups link to the Mg-dominant octahedra of the O sheet adjacent along t 1 . In the O sheet, occurrence of divalent cations at the M O (1) site results in the presence of monovalent anions, F – , at the X O A site. The A P site of the H sheet is occupied mainly by Ba; the A P site is shifted from the plane of the H sheet, and Ba atoms constitute the I block of the composition [Ba 2 ] 4+ . Schüllerite is the only mineral of Group IV that has (1) a brookite-like [Mg 2 O 8 ] 12– chain of octahedra in the O sheet; (2) [5]-coordinated Ti in the H sheet; (3) Ba atoms in the I block. The ideal structural formula of schüllerite is of the form A P 2 M H 2 M O 4 (Si 2 O 7 ) 2 (X O M ) 2 (X O A ) 2 : Ba 2 Ti 2 Na 2 Mg 2 Ti 2 (Si 2 O 7 ) 2 O 2 F 2 , Z = 1.

Description: Sveinbergeite, Ca(Fe2+ 6 Fe3+)Ti2(Si4O12)2O2(OH)5(H2O)4, is a new astrophyllite-group mineral discovered in a syenite pegmatite at Buer on the Vesteroya peninsula, Sandefjord, Oslo Region, Norway. The mineral occurs in pegmatite cavities as 0.01-0.05 mm thick lamellar (0.2-0.5 x 5-10 mm) crystals forming rosette-like divergent groups and spherical aggregates, which are covered by brown coatings of iron (and possibly manganese) oxides, associated with magnesiokatophorite, aegirine, microcline, albite, calcite, fluorapatite, molybdenite, galena and a hochelagaite-like mineral. Crystals of sveinbergeite are deep green with a pale green streak and a vitreous and pearly lustre. Sveinbergeite has perfect cleavage on {001} and a Mohs hardness of 3. Its calculated density is 3.152 g/cm3. It is biaxial positive with 1.745(2), {beta} 1.746(2), {gamma} 1.753(2), 2V(meas.) = 20(3){degrees}. The mineral is pleochroic according to the scheme Z 〉 X [~] Y : Z is deep green, X and Y are brownish green. Orientation is as follows: X {perp} (001), Y ^ b = 12{degrees}, Z = a, elongation positive. Sveinbergeite is triclinic, space group P1, a = 5.329(4), b = 11.803(8), c = 11.822(8) A; = 101.140(8){degrees}, {beta} = 98.224(8){degrees}, {gamma} = 102.442(8){degrees}; V = 699.0(8) A3; Z = 1. The nine strongest lines in the X-ray powder diffraction pattern [d in A(I)(hkl)] are: 11.395(100)(001,010), 2.880(38)(004), 2.640(31)(210,141), 1.643(24)(071,072), 2.492(20)(211), 1.616(15)(070), 1.573(14)(322), 2.270(13)(134) and 2.757(12)(140,132). Chemical analysis by electron microprobe gave Nb2O5 0.55, TiO2 10.76, ZrO2 0.48, SiO2 34.41, Al2O3 0.34, Fe2O3 5.57, FeO 29.39, MnO 1.27, CaO 3.87, MgO 0.52, K2O 0.49, Na2O 0.27, F 0.24, H2O 8.05, O=F -0.10, sum 96.11 wt.%, the amount of H2O was determined from structure refinement, and the valence state of Fe was calculated from structure refinement in accord with Mossbauer spectroscopy. The empirical formula, calculated on the basis of eight (Si + Al) p.f.u., is (Ca0.95Na0.12K0.14){Sigma}1.21(Fe2+ 5.65 Fe3+ 0.93 Mn0.25Mg0.18){Sigma}7.01(Ti1.86Nb0.06Zr0.05 Fe3+ 0.03){Sigma}2(Si7.91Al0.09){Sigma}8O34.61H12.34F0.17, Z = 1. The infrared spectrum of the mineral contains the following absorption frequencies: 3588, [~]3398 (broad), [~]3204 (broad), 1628, 1069, 1009, 942, 702, 655 and 560 cm-1. The crystal structure of the mineral was solved by direct methods and refined to an R1 index of 21.81%. The main structural unit in the sveinbergeite structure is an HOH layer which is topologically identical to that in the astrophyllite structure. Sveinbergeite differs from all other minerals of the astrophyllite group in the composition and topology of the interstitial A and B sites and linkage of adjacent HOH layers. The mineral is named in honour of Svein Arne Berge (b. 1949), a noted Norwegian amateur mineralogist and collector who was the first to observe and record this mineral from its type locality as a potential new species.

Description: The crystal structure of nafertisite, Na 3 Fe 2+ 10 Ti 2 (Si 6 O 17 ) 2 O 2 (OH) 6 F(H 2 O) 2 , from Mt. Kukisvumchorr, Khibiny alkaline massif, Kola peninsula, Russia, a 5.358(1), b 16.204(3), c 21.976(4) Å, β 94.91(1) ° , V 1901.0(7) Å 3 , space group A 2/ m , Z = 2, D calc. 3.116 g/cm 3 , has been refined to an R 1 value of 5.60 % for 2747 observed [ F o 〉 4 F ] unique reflections collected with a single-crystal diffractometer. The crystal used in the collection of the X-ray intensity data was analyzed by electron microprobe; the Fe 3+ /(Fe 2+ +Fe 3+ ) ratio was measured by Mössbauer spectroscopy, and FTIR and Raman spectra were collected. The empirical formula was calculated on the basis of (O + F + OH + H 2 O) = 44.39 pfu : (Na 1.39 K 0.61 ) 2 Na 1 (Rb 0.06 Cs 0.02 0.92 ) 1 (Fe 2+ 9.11 Mg 0.46 Mn 0.22 Al 0.10 Na 0.09 Ca 0.02 ) 10 (Ti 1.90 Nb 0.05 Mg 0.03 Zr 0.02 ) 2 [(Si 11.81 Al 0.19 ) 12 O 34 ]O 2 (OH) 6 (F 0.86 O 0.14 ) 1 (H 2 O) 1.39 ; Z = 2; the content of H 2 O was calculated from the structure-refinement results. The HOH layer is the main structural unit in nafertisite. It consists of a central octahedral (O) sheet and two adjacent heteropolyhedral (H) sheets. The O sheet is composed of Fe 2+ -dominant M(1–3) octahedra, the M (1–3) sites are fully occupied and the ideal composition of the O sheet is Fe 2+ 10 apfu . The H sheet is composed of the nafertisite T 6 O 17 ribbons and Ti-dominant D octahedra. The chemical composition of the nafertisite ribbon is (Si 11.81 Al 0.19 )O 34 apfu , ideally (Si 6 O 17 ) 2 pfu . In the crystal structure of nafertisite, HOH layers alternate with intermediate ( I ) blocks along c . In the I block, the A, B, C and W sites are occupied by (Na 1.39 K 0.61 ), Na, ( 0.92 Rb 0.06 Cs 0.02 ) and [(H 2 O) 1.39 0.61 ] pfu , respectively. The chemical composition of the I block of the general formula A 2 BCW is [(Na 1.39 K 0.61 )Na 1 ( 0.92 Rb 0.06 Cs 0.02 )(H 2 O) 1.39 ] pfu , ideally Na 3 (H 2 O) 2 pfu. Nafertisite is closely related to the astrophyllite-group minerals.

Description: The HOH layer is the main structural unit in the crystal structures of Fe 3+ -disilicates ericssonite-2 O , ideally Ba 2 Fe 3+ 2 Mn 4 (Si 2 O 7 ) 2 O 2 (OH) 2 , ferroericssonite, ideally Ba 2 Fe 3+ 2 Fe 2+ 4 (Si 2 O 7 ) 2 O 2 (OH) 2 , and yoshimuraite, ideally Ba 4 Ti 2 Mn 4 (Si 2 O 7 ) 2 (PO 4 ) 2 O 2 (OH) 2 , a TS-block mineral of Group II. The chemical compositions of the core part of the HOH layer in ericssonite-2 O and ferroericssonite, [5] Fe 3+ 2 Mn 4 (Si 2 O 7 ) 2 O 2 (OH) 2 and [5] Fe 3+ 2 Fe 2+ 4 (Si 2 O 7 ) 2 O 2 (OH) 2 , are similar to the chemical composition of the core part of the HOH layer in yoshimuraite, [5] Ti 4+ 2 Mn 4 (Si 2 O 7 ) 2 O 2 (OH) 2 , except for the cation species at the [5]-coordinated M H site in the H sheets: [5] Fe 3+ and [5] Ti 4+ , respectively. Despite this similarity, the topology of the HOH layer in ericssonite-2 O and ferroericssonite is different from that in yoshimuraite. In TS-block minerals, different distortions of M O octahedra correspond to specific types of linkage of H and O sheets. Topological consideration of Fe 3+ -disilicates ericssonite-2 O and ferroericssonite and yoshimuraite, a TS-block mineral of Group II, shows that different topologies of the chemically identical HOH layer are due to a difference in the bond-valence contributions of Fe 3+ and Ti 4+ at the M H site in the H sheet ( i.e. , inability of Fe 3+ to contribute sufficient bond-valence to the X O M anion) and subsequent different distortions of M O octahedra in the O sheet, where M O = Mn 2+ , Fe 2+ .

Description: A bstract Saamite, BaTiNbNa 3 Ti(Si 2 O 7 ) 2 O 2 (OH) 2 (H 2 O) 2 , is a Group-III TS-block mineral from the Kirovskii mine, Mount Kukisvumchorr, Khibiny alkaline massif, Kola Peninsula, Russia. The mineral occurs as transparent platy crystals 2–10 μm thick and up to 180 μm across. It is colorless to very pale tan, with a white streak and a vitreous luster. The mineral formed in a pegmatite as a result of hydrothermal activity. Associated minerals are natrolite, barytolamprophyllite, kazanskyite, nechelyustovite, hydroxylapatite, belovite-(La), belovite-(Ce), gaidonnayite, nenadkevichite, epididymite, apophyllite-(KF), and sphalerite. Saamite has perfect cleavage on {001}, uneven fracture and a Mohs hardness ca. 3. Its calculated density is 3.243 g/cm 3 . Saamite is biaxial positive with α 1.760, β 1.770, 1.795 ( 589 nm), 2 V meas. = 69(2)°, 2 V calc. = 65°, with medium dispersion, r 〉 v . It is nonpleochroic. Saamite is triclinic, space group P 1 {macron} , a 5.437(2), b 7.141(3), c 21.69(1) Å, α 92.97(1), β 96.07(1), 90.01(1)°, V 836.3(11) Å 3 . The strongest lines in the X-ray powder-diffraction pattern [ d (Å)(I)( hkl )] are: 21.539(100)(001), 2.790(15)(122), 2.692(14)(008), 3.077(13)(007), 7.180(11)(003), 2.865(11)(1 2 {macron} 2), 1.785(9)(1 1 {macron} 4), 2.887(9)( 1 {macron} 22, 0 1 {macron} 7, 115), and 1.785(9)(0 4 {macron} 1, 1 3 {macron} 7, 040, 2 {macron} 2 {macron} 8, 230, 23 1 {macron} ). Chemical analysis by electron microprobe gave Nb 2 O 5 12.24, TiO 2 20.37, SiO 2 29.07, Al 2 O 3 0.08, FeO 0.32, MnO 5.87, MgO 0.04, BaO 11.31, SrO 2.51, CaO 1.76, K 2 O 0.77, Na 2 O 8.39, H 2 O 5.77, F 1.71, O = F –0.72, sum 99.49 wt.%; H 2 O was determined from structure refinement and its presence was confirmed by IR spectroscopy. The empirical formula based on 20 (O + F) atoms pfu is (Ba 0.61 Sr 0.20 K 0.13 0.06 ) 1 ( 0.74 Ca 0.26 ) 1 ( Na 2.22 Mn 0.55 Fe 0.04 2 + 0.19 ) 3 (Ti 2.09 Nb 0.76 Mn 0.13 Mg 0.01 Al 0.01 ) 3 Si 3.97 O 19.26 H 5.26 F 0.74 , Z = 2. The simplified formula is as follows: Ba(,Ca)Ti(Nb,Ti)(Na,Mn) 3 (Ti,Nb)(Si 2 O 7 ) 2 O 2 (OH,F) 2 (H 2 O) 2 . The IR spectrum of saamite contains the following bands: ~1605, 1645, ~1747 and ~3420 cm –1 . The crystal structure was solved by direct methods and refined to an R 1 index of 9.92%. In the crystal structure of saamite, the main structural unit is the TS block, which consists of HOH sheets (H-heteropolyhedral, O-octahedral). The TS block exhibits linkage and stereochemistry typical for Group III [Ti (+ Nb + Mg) = 3 apfu ] of TS-block minerals. The O sheet is composed of Na- and Ti-dominant octahedra and has ideal composition Na 3 Ti apfu . The TS block has two different H sheets where Si 2 O 7 groups link to [5]-coordinated Ti and [6]-coordinated Nb polyhedra, respectively. There are two peripheral sites, [10]-coordinated A P (1) and [8]-coordinated A P (2), occupied mainly by Ba (less Sr and K) at 94% and Ca at 26%, respectively. In the crystal structure of saamite, adjacent TS blocks connect in two different ways: (1) via hydrogen bonds between H 2 O–H 2 O groups and H 2 O–O atoms of adjacent TS blocks; (2) via a layer of Ba atoms that constitute the I block. The TS block, I block and types of self-linkage of TS blocks are topologically identical to those in the nechelyustovite structure. The mineral is named after the Saami (Caam in Cyrillic) indigenous people who inhabit parts of the Kola Peninsula of Russia, far northern Norway, Sweden, and Finland.

Description: Stabilization of the ribosomal complexes plays an important role in translational control. Mechanisms of ribosome stabilization have been studied in detail for initiation and elongation of eukaryotic translation, but almost nothing is known about stabilization of eukaryotic termination ribosomal complexes. Here, we present one of the mechanisms of fine-tuning of the translation termination process in eukaryotes. We show that certain deacylated tRNAs, remaining in the E site of the ribosome at the end of the elongation cycle, increase the stability of the termination and posttermination complexes. Moreover, only the part of eRF1 recognizing the stop codon is stabilized in the A site of the ribosome, and the stabilization is not dependent on the hydrolysis of peptidyl-tRNA. The determinants, defining this property of the tRNA, reside in the acceptor stem. It was demonstrated by site-directed mutagenesis of tRNA Val and construction of a mini-helix structure identical to the acceptor stem of tRNA. The mechanism of this stabilization is different from the fixation of the unrotated state of the ribosome by CCA end of tRNA or by cycloheximide in the E site. Our data allow to reveal the possible functions of the isodecoder tRNAs in eukaryotes.

Description: Kolskyite, (Ca)Na 2 Ti 4 (Si 2 O 7 ) 2 O 4 (H 2 O) 7 , is a Group-IV TS-block mineral from the Kirovskii mine, Mount Kukisvumchorr, Khibiny alkaline massif, Kola Peninsula, Russia. The mineral occurs as single, platy crystals 2–40 μm thick and up to 500 μm across. It is pinkish yellow, with a white streak and a vitreous luster. The mineral formed in a pegmatite as a result of hydrothermal activity. Associated minerals are natrolite, nechelyustovite, kazanskyite, barytolamprophyllite, hydroxylapatite, belovite-(La), belovite-(Ce), gaidonnayite, nenadkevichite, epididymite, apophyllite-(KF), and sphalerite. Kolskyite has perfect cleavage on {001}, splintery fracture, and a Mohs hardness of 3. Its calculated density is 2.509 g/cm 3 . Kolskyite is biaxial negative with α 1.669, β 1.701, 1.720 ( 590 nm), 2 V meas. = 73.6(5)°, 2 V calc. = 74.0°, with no discernible dispersion. It is nonpleochroic. Kolskyite is triclinic, space group P , a 5.387(1), b 7.091(1), c 15.473(3) Å, α 96.580(4), β 93.948(4), 89.818(3)°, V 585.8(3) Å 3 . The strongest lines in the X-ray powder-diffraction pattern [ d (Å)(I)( hkl )] are: 15.161(100)(001), 2.810(19)(121, 12), 3.069(12) (005), 2.938(10)(1,120,11), 2.680(9)(3, 200,114, 01), 1.771(9) (04,040), 2.618(8)(13,122), 2.062(7)(221,22,3,22), and 1.600(7)(2,320,320). Chemical analysis by electron microprobe gave Nb 2 O 5 6.96, ZrO 2 0.12, TiO 2 26.38, SiO 2 27.08, FeO 0.83, MnO 2.95, MgO 0.76, BaO 3.20, SrO 5.21, CaO 4.41, K 2 O 0.79, Na 2 O 6.75, H 2 O 13.81, F 0.70, O = F –0.29, sum 99.66 wt.%; H 2 O was determined from structure solution and refinement. The empirical formula was calculated on 25 (O + F) apfu : (Na 1.93 Mn 0.04 Ca 0.03 ) 2 (Ca 0.67 Sr 0.45 Ba 0.19 K 0.15 ) 1.46 (Ti 2.93 Nb 0.46 Mn 0.33 Mg 0.17 Fe 2+ 0.10 Zr 0.01 ) 4 Si 4.00 O 24.67 H 13.60 F 0.33 , Z = 1. Simplified and ideal formulae are as follows: (Ca,) 2 Na 2 Ti 4 (Si 2 O 7 ) 2 O 4 (H 2 O) 7 and (Ca)Na 2 Ti 4 (Si 2 O 7 ) 2 O 4 (H 2 O) 7 . The FTIR spectrum of the mineral contains the following bands: ~3300 cm –1 (very broad) and ~1600 cm –1 (sharp). The crystal structure was solved by direct methods and refined to an R 1 index of 8.8%. The crystal structure of kolskyite is a combination of a TS (titanium-silicate) block and an I (intermediate) block. The TS block consists of HOH sheets (H-heteropolyhedral, O-octahedral). The TS block exhibits linkage and stereochemistry typical for Group IV [Ti (+ Mg + Mn) = 4 apfu ] of Ti-disilicate minerals. In the H sheet in kolskyite, Si 2 O 7 groups link to [6]-coordinated Ti octahedra. In the O sheet, Ti-dominant and Na octahedra each form brookite-like chains. There is one peripheral A P site occupied mainly by Ca (less Sr, Ba, and K) at 68%. The I block consists of H 2 O groups and A P atoms. The I block is topologically identical to those in the kazanskyite and nechelyustovite structures. The mineral is named after the Kola Peninsula ( Kolskyi Poluostrov in Russian). The chemical formula and structure of kolskyite were predicted by Sokolova & Cámara (2010) ; this is the first correct prediction of a TS-block mineral.

Description: New developments in crystal chemistry have been considered for 34 titanium disilicate minerals that contain the TS (Titanium-Silicate) block, a central trioctahedral (O) sheet, and two adjacent heteropolyhedral (H) sheets of [5–7]-coordinated polyhedra and Si 2 O 7 groups. The general formula of the TS block is A P 2 B P 2 M H 2 M O 4 (Si 2 O 7 ) 2 X 4+n , where M H 2 and M O 4 = cations of the H and O sheets; M H = Ti, Nb, Zr, Mn, Ca + REE, Ca; M O = Ti, Zr, Nb, Fe 2+ , Mg, Mn, Ca, Na; A P and B P = cations at the peripheral ( P ) sites = Na, Ca + REE, Ca, Ba, Sr, K; X = anions, O, OH, F, and H 2 O groups; X 4+n = X O 4 + X P n , n = 0, 1, 1.5, 2, 4. There are three topologically distinct TS blocks based on three types of linkage of H and O sheets. In the crystal structures of TS-block minerals, TS blocks either link directly or alternate with intermediate ( I ) blocks. The I block consists of alkali and alkaline-earth cations, oxyanions (PO 4 ), (SO 4 ) and (CO 3 ), and H 2 O groups. There are four groups of TS-block structures, based on the topology and stereochemistry of the TS block: Groups I, II, III, and IV, where Ti (+ Nb + Zr + Mg + Mn) = 1, 2, 3, and 4 apfu , respectively. In a TS-block structure, four types of self-linkage between adjacent TS blocks occur. The concept of basic and derivative structures has been introduced for TS-block minerals. A basic structure has the following four characteristics: (1) there is only one type of TS block; (2) the two H sheets of the TS block are identical; (3) there is only one type of I block, or it is absent; and (4) there is only one type of self-linkage of TS blocks. Basic structures obey the general structural principles of Sokolova (2006) . A derivative structure has one or more of the three following characteristics: (1) there is more than one type of TS block; (2) there is more than one type of I block; (3) there is more than one type of self-linkage of TS blocks. A derivative structure is related to two or more basic structures of the same Group: it can be derived by adding these structures via sharing the central O sheet of the TS blocks of adjacent structural fragments which represent basic structures . There are 30 basic TS-block structures and four derivative TS-block structures. Based on established relations between basic and derivative structures, possible atomic arrangements and chemical formulae have been predicted for 12 derivative structures and two basic structures.

Description: An immense amount of agricultural waste is produced while growing, harvesting and processing goods; which should be treated as a resource for its prevalence and renewability. While developed countries are concerned with utilization and environmental issues, developing countries are focusing on the economic factors of social housing, especially in rural areas. Fortunately, environmental awareness has been raised in the construction industry by using agricultural waste as partial replacement for fine aggregate, coarse aggregate, reinforcing materials, cement and binders. This review is an attempt to collect world-wide data with references for future estimation possibilities of agro waste application focused on fine aggregate replacement in concrete.