The discreditation of oboyerite and a note on the crystal structure of plumbotellurite

2019 ◽  
Vol 83 (6) ◽  
pp. 791-797
Author(s):  
Owen P. Missen ◽  
Michael S. Rumsey ◽  
Anthony R. Kampf ◽  
Stuart J. Mills ◽  
Malcolm E. Back ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Los Angeles ◽  
Natural History ◽  
Type Specimen ◽  
Natural History Museum ◽  
X Ray Diffraction ◽  
Synthetic Compound ◽  
History Museum ◽  
X Ray ◽  
International Mineralogical Association

AbstractThe mineral ‘oboyerite’, first described in 1979 from the Grand Central mine, Tombstone, Cochise County, Arizona, USA, has been re-examined. The type specimen from the Natural History Museum, London and a specimen from the Natural History Museum of Los Angeles County (traceable to S. A Williams, who first described ‘oboyerite’) were analysed in this study. The discreditation of ‘oboyerite’ as a valid mineral species has been approved by the Commission on New Minerals, Nomenclature and Classification of the International Mineralogical Association (Proposal 19-D). Single-crystal X-ray diffraction, powder X-ray diffraction, electron probe microanalysis and scanning electron microscopy were all employed to show that ‘oboyerite’ is formed of at least two distinct phases, including the lead–tellurium oxysalt minerals ottoite and plumbotellurite. During the course of the discreditation, plumbotellurite was confirmed to be identical to the synthetic compound α-Pb2+Te4+O3. Previously, in some mineralogical literature plumbotellurite was described as orthorhombic with no known crystal structure.

scholarly journals James Hamilton McLean: The master of the Gastropoda

Zoosymposia ◽  
2019 ◽  
Vol 13 (1) ◽  
pp. 14-43
Author(s):  
LINDSEY T. GROVES ◽  
DANIEL L. GEIGER ◽  
JANN E. VENDETTI ◽  
EUGENE V. COAN
Keyword(s):  
Los Angeles ◽  
Natural History ◽  
Los Angeles County ◽  
Natural History Museum ◽  
Current Status ◽  
History Museum ◽  
Type Information

A biography of the late James H. McLean, former Curator of Malacology at the Natural History Museum of Los Angeles County is provided. It is complemented with a full bibliography and list of 344 taxa named by him and co-authors (with type information and current status), as well as 40 patronyms.

Mold Removal and Rehousing of the Ichthyology and Herpetology Skeletal Collections at the Natural History Museum of Los Angeles County

Copeia ◽  
2008 ◽  
Vol 2008 (4) ◽  
pp. 737-741 ◽  
Author(s):  
Christine E. Thacker ◽  
Richard F. Feeney ◽  
Neftali A. Camacho ◽  
Jeffrey A. Seigel
Keyword(s):  
Los Angeles ◽  
Natural History ◽  
Los Angeles County ◽  
Natural History Museum ◽  
History Museum ◽  
Skeletal Collections

Fibrous Minerals and Synthetic Fibers

1989 ◽  
Author(s):  
H. Catherine W. Skinner ◽  
Malcolm Ross ◽  
Clifford Frondel
Keyword(s):  
Crystal Structure ◽  
Chemical Composition ◽  
Chemical Properties ◽  
Type Specimen ◽  
Mineral Species ◽  
X Ray Diffraction ◽  
X Ray ◽  
Synthetic Fibers ◽  
Fibrous Minerals ◽  
The Common

A mineral is a naturally occurring, crystalline inorganic compound with a specific chemical composition and crystal structure. Minerals are commonly named to honor a person, to indicate the geographic area where the mineral was discovered, or to highlight some distinctive chemical, crystallographic, or physical characteristic of the substance. Each mineral sample has some obvious properties: color, shape, texture, and perhaps odor or taste. However, to determine the precise composition and crystal structure necessary to accurately identify the species, one or several of the following techniques must be employed: optical, x-ray diffraction, transmission electron microscopy and diffraction, and chemical and spectral analyses. The long history of bestowing names on minerals has provided some confusing legacies. Many mineral names end with the suffix “ite,” although not most of the common species; no standard naming practice has ever been adopted. Occasionally different names have been applied to samples of the same mineral that differ only in color or shape, but are identical to each other in chemical composition and crystal structure. These names, usually of the common rock-forming minerals, are often encountered and are therefore accepted as synonyms or as varieties of bona fide mineral species. The Fibrous Minerals list (Appendix 1) includes synonyms. A formal description of a mineral presents all the physical and chemical properties of the species. In particular, distinctive attributes that might facilitate identification are noted, and usually a chemical analysis of the first or “type” specimen on which the name was originally bestowed is included. As an example, the complete description of the mineral brucite (Mg(OH)2), as it appears in Dana’s System of Mineralogy, is presented as Appendix 3. Note the complexity of this chemically simple species and the range of information available. In the section on Habit (meaning shape or morphology) both acicular and fibrous forms are noted. The fibrous variety, which has the same composition as brucite, is commonly encountered (see Fig. 1.1D) and is known by a separate name, “nemalite.” Tables to assist in the systematic determination of a mineral species are usually based on quantitative measurements of optical properties (using either transmitted or reflected light, as appropriate) or on x-ray diffraction data.

scholarly journals Belomarinaite KNa(SO4): A new sulfate from 2012–2013 Tolbachik Fissure eruption, Kamchatka Peninsula, Russia

2019 ◽  
Vol 83 (4) ◽  
pp. 569-575 ◽  
Author(s):  
Stanislav K. Filatov ◽  
Andrey P. Shablinskii ◽  
Lidiya P. Vergasova ◽  
Olga U. Saprikina ◽  
Rimma S. Bubnova ◽  
...  
Keyword(s):  
Crystal Structure ◽  
Kamchatka Peninsula ◽  
Fissure Eruption ◽  
Synthetic Analogue ◽  
X Ray Diffraction ◽  
Synthetic Compound ◽  
X Ray ◽  
Mohs Hardness ◽  
Average Size ◽  
Cation Sites

AbstractBelomarinaite, ideally KNaSO4, is a new sulfate mineral discovered in the Toludskoe lava field, formed during the 2012–2013 Tolbachik Fissure eruption. The mineral occurs as arborescent aggregates of tabular crystals (1 mm × 0.3 mm × 0.1 mm) comprising hematite impurities. The average size of the aggregates is 0.5–0.7 mm. The empirical formula is (K0.95Na0.92Cu0.04)Σ1.91S1.01O4. The crystal structure of belomarinaite was determined using single-crystal X-ray diffraction data; the space group isP3m1,a= 5.6072(3),c= 7.1781(4) Å,V= 195.45(2) Å3,Z= 2 andR1= 2.6%. In the crystal structure of belomarinaite, there are six cation sites: the[4]S1 and[4]S2 sites are occupied by S, the[6]Na and[12]K sites are occupied by Na and K, respectively, giving Na0.5K0.5apfu and the[10]M1 and[10]M2 sites are occupied by Na0.78K0.22and K0.78Na0.22apfu, respectively. The crystal structure is a framework of SO4tetrahedra, Na octahedra and K,M1 andM2 polyhedra. Belomarinaite is isostructural with the synthetic compound KNaSO4. In belomarinaite, Na and K are disordered overM1 andM2 sites; in its synthetic analogue, Na and K are ordered overM1 andM2 sites, respectively. The Mohs’ hardness is 2–3. The mineral is uniaxial (+), with ω = 1.485(3) and ε = 1.488(3) (λ = 589 nm). The strongest lines of the powder X-ray diffraction pattern [d, Å (I, %) (hkl)] are: 4.022(31)(101); 3.591(26)(002); 2.884(74)(102); 2.800(100)(110); 2.391(16)(003); 2.296(8)201; 2.008(38)(022); and 1.634(10)(212). The mineral was named in honour of Russian volcanologist Marina Gennadievna Belousova (b. 1960) for her significant contributions to the monitoring of the Tolbachik Fissure eruption.

scholarly journals Urban Nature Gardens at the Natural History Museum of Los Angeles County attract “wildlife spectacle” of insect pollinators

Zoosymposia ◽  
2018 ◽  
Vol 12 (1) ◽  
pp. 29-50 ◽  
Author(s):  
EMILY A. HARTOP ◽  
ELIZABETH LONG ◽  
CAROL BORNSTEIN ◽  
LISA GONZALEZ ◽  
BRIAN V. BROWN
Keyword(s):  
Los Angeles ◽  
Natural History ◽  
Los Angeles County ◽  
Natural Habitat ◽  
Natural History Museum ◽  
Insect Fauna ◽  
History Museum ◽  
Natural Site ◽  
Abundance And Diversity ◽  
Flower Flies

The newly-constructed Nature Gardens at the Natural History Museum of Los Angeles County (California, USA) were purposefully built to attract wildlife. In this study we wanted to find out to what extent this manufactured environment is successful in attracting native insect fauna to the urban core of the city when compared to the surrounding neighborhoods or natural areas on the periphery of Los Angeles. To determine this, a one-year Malaise trap catch from the Nature Gardens was compared with samples from four neighboring sites within a five-kilometer radius, as well as a site adjacent to natural habitat located sixteen kilometers away. Our analysis focused on the diversity and abundance of three pollinator groups: bees, flower flies and butterflies contrasted with a single non-pollinator group: scuttle flies.        Our findings show that the Nature Gardens support greater abundance and diversity than any of the nearby sites or the natural site for all pollinator taxa examined. In contrast, the natural site supported much higher abundance and diversity of the non-pollinator scuttle flies when compared to the Nature Gardens. Calculated evenness of all taxa was lower in the Nature Gardens than at the natural site and Shannon Diversity indices were highest in the Nature Gardens for flower flies and butterflies, but lower in the Nature Gardens than at the natural site for bees and scuttle flies. These results indicate that biodiversity in an urban environment can be selectively manipulated through management of green spaces, but may not duplicate the communities found in natural spaces. Rather, targeted management (through plantings, ground cover and other substrates, watering, pest management techniques, etc.) can increase fauna predictively to create a “wildlife spectacle” of charismatic microfauna.

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