The identity of ‘eggonite’ with sterrettite

1941 ◽  
Vol 26 (175) ◽  
pp. 131-133 ◽  
Author(s):  
F. A. Bannister
Keyword(s):  
British Museum ◽  
New Mineral ◽  
Aluminium Phosphate ◽  
X Ray ◽  
Phosphate Mineral ◽  
Cell Dimensions

During the X-ray study of a new phosphate mineral, not yet published, the usual comparison was made with cell-side measuremerits of related minerals. One of these is ‘eggonite’, a rare hydrous aluminium phosphate said to occur on silver ores at Felsőbánya, Hungary. Rotation photographs of ‘eggonite’ are different from those of the new mineral, but yielded dimensions close to those of sterrettite, a new mineral from Fairfield, Utah, described last year by Larsen and Montgomery. These authors generously presented a specimen of sterrettite to the British Museum, and rotation photographs taken in the Mineral Department not only give cell-dimensions close to those published but also identical with those of ‘eggonite’. A brief account of this identification is now given not only to justify abandoning the mineral name ‘eggonite’, but also to place on record a European occurrence of a rare mineral so far described from only one American locality.

An X-Ray study of schultenite

1950 ◽  
Vol 29 (211) ◽  
pp. 287-290 ◽  
Author(s):  
G. F. Claringbull
Keyword(s):  
British Museum ◽  
Original Description ◽  
New Mineral ◽  
X Rays ◽  
X Ray ◽  
Cell Dimensions ◽  
South West Africa ◽  
Unit Cell Dimensions ◽  
Plate Distance ◽  
High Absorption

In 1926 schultenite from Tsumeb, Otavi, South-West Africa, was described as a new mineral by L. J. Spencer and related to the compound PbHAsO4. The specimen on which the original description was based is still unique in the British Museum collection and was used for the present study. There appears to be no record in the literature that the mineral has been discovered in any other localityFor the X-ray examination rather small fragments (less than 0·1 × 0·05 mm.) were broken from pieces of crystals since all the available crystals were too large and the material has a high absorption to X-rays. Single crystal rotation, oscillation, and Weissenberg photographs in 6-cm. diameter cameras with Cu-Kα radiation as well as Laue photographs (crystal-plate distance 4 cm.) with tungsten radiation were used to derive the unit-cell dimensions and space-group.

Killalaite, a new mineral from Co. Sligo, Ireland

1974 ◽  
Vol 39 (305) ◽  
pp. 544-548 ◽  
Author(s):  
R. Nawaz
Keyword(s):  
Refractive Index ◽  
Microprobe Analysis ◽  
Electron Microprobe Analysis ◽  
British Museum ◽  
New Mineral ◽  
Secondary Mineral ◽  
X Ray ◽  
Cell Dimensions ◽  
Hydrothermal Environment ◽  
Bow Tie

SummaryKillalaite occurs in a thermally metamorphosed limestone at Killala Bay, near Inishcrone, Co. Sligo. It is a secondary mineral and occurs in cavities and veins with calcite or afwillite in spurrite-wollastonite rocks. It is found in well-formed colourless crystals, up to 2 mm long, with a characteristic penetrative twinning observed under crossed nicols as a cross ‘bow-tie’, cleavage (100) perfect, (010) good, (001) poor. The crystals are monoclinic, biaxial, 2Vα26°, refractive index α 1·635 and γ 1·642, optic axial plane (010), β = [010] (elongation), γ: [001] ≈ 16°, density calculated from RI ∼ 2·88, provisional approximate cell dimensions a 9·3, b 9·9, c 7·7 (±0.1 Å), β ∼105° and Z = 2. Electron microprobe analysis gave CaO 57·o, SiO2 39·8; H2O (by difference) 3·2; MgO, Al2O3, and Fe2O3 together < 0·3 weight %, composition 2Ca3Si2O7.H2O. The stronger lines of the X-ray powder pattern are: 3·03, 2·824, 2·724, 2·275, 2·224, 1·688, 1·673, and 1·413 Å. It probably formed in a CO2-deficient hydrothermal environment in the PT range of 350° to 500 °C and 500 to 3500 bars. The mineral is named after the name of the locality, Killala Bay, and should be pronounced as killalahite. Type material is preserved at the Ulster Museum and at the British Museum (Natural History).

Refinement of the crystal structure of sieleckiite and revision of its symmetry

2017 ◽  
Vol 81 (4) ◽  
pp. 917-922
Author(s):  
Peter Elliott
Keyword(s):  
Crystal Structure ◽  
Synchrotron Radiation ◽  
Single Crystal ◽  
Diffraction Data ◽  
X Ray Diffraction ◽  
Aluminium Phosphate ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Phosphate Mineral

AbstractThe crystal structure of the copper aluminium phosphate mineral sieleckiite, Cu3Al4(PO4)2 (OH)12·2H2O, from the Mt Oxide copper mine, Queensland, Australia was solved from single-crystal X-ray diffraction data utilizing synchrotron radiation. Sieleckiite has monoclinic rather than triclinic symmetry as previously reported and is space group C2/m with unit-cell parameters a = 11.711(2), b = 6.9233(14), c = 9.828(2) Å, β = 92.88(3)°, V = 795.8(3) Å3and Z = 2. The crystal structure, which has been refined to R1 = 0.0456 on the basis of 1186 unique reflections with Fo > 4σF, is a framework of corner-, edge- and face- sharing Cu and Al octahedra and PO4 tetrahedra.

Kingite, a new hydrated aluminium phosphate mineral from Robertstown, South Australia

1957 ◽  
Vol 31 (236) ◽  
pp. 351-357 ◽  
Author(s):  
K. Norrish ◽  
Lillian E. R. Rogers ◽  
R. E. Shapter
Keyword(s):  
Refractive Index ◽  
Chemical Composition ◽  
Specific Gravity ◽  
Diffraction Pattern ◽  
South Australia ◽  
X Ray Diffraction ◽  
Aluminium Phosphate ◽  
X Ray ◽  
Phosphate Mineral ◽  
Hydrated Aluminium

SummaryA new hydrated aluminium phosphate mineral, kingite, from phosphate workings near Robertstown, South Australia, has an idealized formula Al2O3.Al(OH)3.P2O5.9H2O, with some replacement of OH by F. The specific gravity is 2·2 to 2·3, refractive index 1·514, and percentage chemical composition Al2O3 31·92, P2O5 28·63, H2O 37·93. The three strongest lines on the X-ray diffraction pattern are 9·1, 3·45, and 3·48 Å. Kingite changes to a less hydrated phase between 154° C. and 163° C., which is also considered to be a new aluminium phosphate (meta-kingite) with idealized formula Al2O3.Al(OH)3.P2O5.4H2O. The strongest lines of its X-ray diffraction pattern are at 7·4, 5·02, and 37·19 Å.

Kintoreite, PbFe3(PO4)2(OH,H2O)6, a new mineral of the jarosite-alunite family, and lusungite discredited

1995 ◽  
Vol 59 (394) ◽  
pp. 143-148 ◽  
Author(s):  
A. Pring ◽  
W. D. Birch ◽  
J. Dawe ◽  
M. Taylor ◽  
M. Deliens ◽  
...  
Keyword(s):  
Solid Solution ◽  
Iron Phosphate ◽  
Type Specimen ◽  
New Mineral ◽  
Calculated Density ◽  
X Ray ◽  
Yellowish Green ◽  
South Wales ◽  
Phosphate Mineral ◽  
Associated Species

AbstractKintoreite is a new lead iron phosphate mineral in the alunite-jarosite family, from Broken Hill, New South Wales, Australia. It is the phosphate analogue of segnitite and the iron analogue of plumbogummite. Kintoreite occurs as clusters and coatings of cream to yellowish green rhombohedral crystals up to 2 mm high and with the principal form {112}. The mineral also forms waxy, yellowish green globular crusts and hemispheres on other phosphate minerals. These associated species include pyromorphite, libethenite, rockbridgeite/dufrenite, apatite and goethite. Kintoreite formed during oxidation of primary ore rich in galena, in the presence of solutions with high P/(As + S) ratios. The mineral is named for the locality, the Kintore opencut, in which it is most common. A mineral closely resembling kintoreite in composition has also been found at several mines in Germany. Type material is preserved in the Museum of Victoria and the South Australian Museum.Electron microprobe analysis showed a nearly complete spread of compositions across the P-dominant portion of the segnitite-kintoreite series. The selected type specimen has an empirical formula of Pb0.97(Fe2.95Zn0.13Cu0.02)Σ3.10[(PO4)1.30(AsO4)0.39(SO4)0.18(CO3)0.11]Σ1.98(OH)5.45·0.74H2O, calculated on the basis of 14 oxygens and with all Fe trivalent. The simplified formula is PbFe3(PO4)2(OH,H2O)6. Kintoreite crystals are translucent with a vitreous to adamantine lustre, with globules appearing waxy. The streak is pale yellowish green and the Mohs hardness is ∼ 4. Crystals show good cleavage on {001} and are brittle with a rough fracture. The calculated density is 4.34 g cm−3. Kintoreite crystals are uniaxial negative with RIs between 1.935 and 1.955 and show light yellowish green to medium yellow pleochroism.The strongest lines in the X-ray powder pattern are (dobs, Iobs, hkl) 3.07(100) 113; 5.96(90)101; 3.67(60)110; 2.538(50)024; 2.257(50)107; 1.979(50)303; 1.831(40)220. The X-ray data were indexed on a hexagonal unit cell by analogy with beudantite, giving a = 7.325(1) Å, c = 16.900(3) Å, V = 785.3(5) Å3 and Z = 3. The probable space group is Rm, by analogy with beudantite and other members of the alunite-jarosite family. Powder X-ray diffraction data for several intermediate members suggest that the segnitite-kintoreite series may not represent ideal solid solution.During the study of kintoreite, part of the type specimen of lusungite from Zaïre was obtained and shown to be goyazite. The IMA's Commission on New Minerals and Mineral Names has voted to discredit lusungite as a species, and has approved the renaming of the ‘lusungite’ group as the segnitite group. However, as relationships between crystal structure, order-disorder and solid solution in the Pb-rich minerals of the alunite-jarosite family are not well documented, the nomenclatural changes resulting from this study should be seen as interim only.

An X-ray investigation of some rare-earth silicates: cerite, lessingite, beckelite, britholite, and stillwellite

1957 ◽  
Vol 31 (237) ◽  
pp. 455-468 ◽  
Author(s):  
P. Gay
Keyword(s):  
Rare Earth ◽  
New Mineral ◽  
Hexagonal Cell ◽  
Space Group ◽  
X Ray ◽  
Ideal Formula ◽  
Dimensional Approximation ◽  
Cell Dimensions ◽  
Diffraction Patterns ◽  
Probable Space

SummaryAn X-ray study of a number of rare-earth silicates has been carried out; single-crystal and powder data are presented.It is found that cerites can contain up to at least 6 % CaO without disruption of the structure, which is trigonal with probable space-group P321 etc. The cell dimensions are a ca. 10·8 Å., c ca. 37–38 Å., although there is a strong pseudo-cell with halved c-axis. An ideal formula (Ca,Ln†)3Si2(O,OH,F)9 is proposed for this series.Lessingite and beckelite can be regarded chemically as lime-rich members of this cerite series. They do not, however, have the same crystal structure as cerite; their diffraction patterns are very similar to that of britholite, and indicate a structure dimensionally comparable with apatite. For a hexagonal cell, the dimensions are a ca. 9·7 Å., c ca. 7·1 Å., with probable space-group P63, &c. An ideal formula (Ca,Ln)2(Si,Al,P)(O,OH,F)5 is proposed for this series. Marked biaxial optical properties suggest that the structure may be truly orthorhombic, with a very close dimensional approximation to a hexagonal cell.The new mineral, stillwellite, is unrelated to either of these series. It is trigonal with cell dimensions a ca. 6·9 Å., c ca. 6·7 Å., with probable space-group P3112. An ideal formula (Ca,Ln)(Si,Al,P)B(O,OH,F)5 suggested by previous work is confirmed.

Sweetite, a new mineral from Derbyshire

1984 ◽  
Vol 48 (347) ◽  
pp. 267-269 ◽  
Author(s):  
A. M. Clark ◽  
E. E. Fejer ◽  
A. G. Couper ◽  
G. C. Jones
Keyword(s):  
Chemical Analysis ◽  
Powder Pattern ◽  
Tetragonal Symmetry ◽  
New Mineral ◽  
X Ray ◽  
Naturally Occurring ◽  
Cell Dimensions

AbstractSweetite, naturally occurring Zn(OH)2 with tetragonal symmetry, has been found at Milltown, near Ashover, Derbyshire. It occurs as colourless or whitish bipyramids up to 1 mm in size scattered over the surface of colourless fluorite cubes. The cell dimensions are α 8,222 and c 14.34Å with Z = 20. The strongest lines of the X-ray powder pattern are (d, I, hkl): 4.53 37 (112); 3.572 60 (004,202,211); 2.922 100 (213,220); 2.708 18 (105,204); 2.257 17 (224,215,321); 1.840 11 (226,420,413); 1.764 24 (316). Sweetite is uniaxial negative, ω 1.635, ɛ 1.628. Dmeas is close to 3.33 and Dcalc 3.41. Chemical analysis gave 84.3% ZnO and 17.0% H2O, while theoretical figures for Zn(OH)2 are 81.9 and 18.1% respectively.

The identity of minervite and palmerite with taranakite

1947 ◽  
Vol 28 (196) ◽  
pp. 31-35 ◽  
Author(s):  
F. A. Bannister ◽  
G. E. Hutchinson
Keyword(s):  
New Zealand ◽  
Specific Gravity ◽  
Gravity Data ◽  
South Australia ◽  
British Museum ◽  
Museum Collections ◽  
Aluminium Phosphate ◽  
X Ray ◽  
Aluminium Silicate ◽  
Striking Contrast

The abundance of the well-known potassium aluminium silicate minerals, orthoclase, microcline, and muscovite, stands in striking contrast with the rarity of the little-known potassium aluminium phosphate minerals. The only one of these which occurs as distinct crystals and which has yielded a satisfactory formula is minyulite, KAl2(PO4)2(OH,F).4H2O. This mineral was first described by E. S. Simpson and LeMesurier from Western Australia in 1933 and an examination of well-crystallized specimens from South Australia by L. J. Spencer et alii was published in 1943. Spencer's paper included X-ray single-crystal and powder data for minyulite. X-ray, optical, and specific gravity data were also determined at that time for a few other hydrous potassium aluminium phosphate minerals from the British Museum collections. These included palmerite from guano deposits in a large cavern, Monte Alburno, near Controne in Salerno, Italy, presented by E. Casoria who described the mineral in 1904, and taranakite from the Sugarloaves, near New Plymouth, Taranaki, New Zealand.

Sinhalite (MgAlB04), a new mineral. (With Plate XXVII)

1952 ◽  
Vol 29 (217) ◽  
pp. 841-849 ◽  
Author(s):  
G. F. Claringbull ◽  
Max H. Hey
Keyword(s):  
United States ◽  
New Species ◽  
Natural History ◽  
British Museum ◽  
The United States ◽  
New Mineral ◽  
National Museum ◽  
X Ray ◽  
Suitable Material ◽  
A New Species

The investigation which has led to this description of a new mineral began because of a suggestion by Dr. W. F. Foshag, when on a Visit in 1951 to the Mineral Gallery of the British Museum (Natural History), that a brown cut gemstone exhibited as olivine had perhaps been incorrectly determined. More recently, Dr. Foshag has stated that the idea came from Dr. George Switzer, who as a result of an X-ray powder photograph taken in June 1950 of a similar specimen in the collection of the United States National Museum in Washington concluded that his material was not olivine and was likely to be a new species. The present work would not have been pursued had it been realized at the time that Dr. Switzer intended to continue the study when he had suitable material for analysis.

A hydrated barium-strontium pyrochlore in a biotite rock from Panda Hill, Tanganyika

1959 ◽  
Vol 32 (244) ◽  
pp. 10-25 ◽  
Author(s):  
E. Jäger ◽  
E. Niggli ◽  
A. H. Van der Veen
Keyword(s):  
Pyrochlore Structure ◽  
Exchange Capacity ◽  
New Mineral ◽  
Hydroxyl Groups ◽  
X Ray Diffraction ◽  
X Ray ◽  
Barium Strontium ◽  
Cell Dimensions ◽  
Unit Cell Dimensions ◽  
The Ideal

SummaryA hydrated barium-strontium pyrochlore with only subordinate amounts of Ca and Na has been found in a weathered biotite rock (contact-rock of a carbonatite) from Panda Hill, Tanganyika, as small euhedral yellowish-grey cubic crystals (showing the combination of the octahedron and the cube) in a rock containing euhedral biotite, some orthoclase, and several other minerals. Hydrated Ba-Sr pyrochlore is isotropic, the refractive index varies from 2·07 to 2·10. The reflectivity (vertical illumination) is 13·2 %. H. Poor {111} cleavage. The pyrochlore structure (space-group O7h–Fd3m) and the unit-cell dimensions (a 10·562 Å.) are derived from X-ray powder and Weissenberg photographs. The calculated specific gravity is 4·01 (observed, 4·00 on dried material). Chemical analysis gives BaO 12·5, SrO 6·4, Na2O 0·28, K2O 0·25, CaO 1·35, rare earths (mainly Ce2O3) 2, ThO2 0·6, FeO 0·45, TiO2 3·9, Nb2O5 67·0, Ta2O5 0·22, H2O+ 4·0, other constituents 2·21, total 101·16. After deduction for impurities the following formula resulted: (Ba0·30Sr0·22Ca0·05Ce0·04Na0·03Fe0·02K0·01Th0·01)(Nb1·83Ta0·004Ti0·17)O5·61(H2O)0·80.The ideal formula for pyrochlore is A2B2O6(F,OH). In the mineral described only a third of the A-positions are occupied by Ba, Sr, etc. Infra-red spectrophotometry does not indicate hydroxyl-groups. When the mineral is treated with TINO3 solution the intensities of the X-ray diffraction lines 333/511, and 444 are changed; hydrated Ba-Sr pyrochlore shows a certain exchange-capacity.The name pandaite, from Panda Hill, is proposed for the new mineral.

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