无色透明斜长石的基本特征及晕彩成因研究

无色透明斜长石具有多种晕彩色,发育聚片双晶和解理,外观与月光石相似,且不易鉴别。本文通过偏光显微镜、电子探针、X射线粉晶衍射、扫描电镜、透射电镜等测试,对无色透明斜长石的基本宝石学特征、矿物成分和结构特征进行研究,并根据光的薄膜干涉及光栅衍射原理,对其晕彩效应的成因进行探讨。研究结果表明:标本为钙长石及钠长石的类质同相混晶,端员分子式为Ab_(51.84)An_(46.04)Or_(2.11),属于中长石;由于钙长石(An)含量较低,因而折射率、相对密度低于标准拉长石,高于月光石,由此可与相似宝石区分;样品包裹体、双晶结构及晶胞参数对晕彩色的影响较小;解理厚度约为1～4μm,不会因发生薄膜干涉而产生晕彩,但可以发生光栅式衍射而对晕彩效应产生作用;透射电镜测试表明,斜长石晕彩的颜色与出溶条纹厚度之间存在联系,晕彩可由内部出溶的层状结构对光形成薄膜干涉导致。     

长石类宝石又添新秀

宝石世界中的长石家族千姿百态,如斯里兰卡的蓝色冰长石晕彩月长石、马尔加什共和国的金黄色正长石、南非的蓝绿色微斜长石(天河石)、Eiffel(德国)的烟棕色透长石、Myanmar(缅甸)的无色钠长石、印度的红棕色色闪动的日长石(奥长星彩石)、俄勒冈plush的绿色和红色微斜长石。前不久,在肯尼亚的一含蓝晶石伟晶岩中,发现了品质非凡的绿色/浅蓝色可琢磨长石,这一泛绿蓝色长石的问世,使长石类宝石家族中又添新秀。     

斜长石的晕彩效应

斜长石的晕彩效应Ｒ．Ａ．Ｈｏｗｉｅ从１７７０年首次发现晕彩拉长石来，这种独特的光学效应一直为矿物学家和珠宝爱好者所喜爱。ＬｏｒｄＲａｙｌｅｉｇｈ（１９２３）和Ｂｇｇｉｌｄ（１９２４）对其分别作过细致的科学研究。在以后的二三十年里人们逐渐认识到这种现...     

注胶晕长石的鉴定方法

近期,国家黄金钻石制品质量监督检验中心对一串具蓝色晕彩的长石手链样品进行常规检测时,在长波紫外灯下多数珠子发中等强度的蓝白色荧光,且荧光在珠子中呈线状分布。为了对该长石样品进行准确定名,并探究其紫外荧光产生的原因,对其进行了常规宝石学检测、电子探针和红外光谱测试与分析。结果显示,该样品的折射率约为1.53,在显微镜下具有层状结构和针片状包裹体,结合其电子探针的分析结果,确定该样品为晕长石,即具有蓝色晕彩的钠长石;基于样品表面具有典型的"蚯蚓行踪"纹路、沿裂隙发出的紫外荧光及红外光谱下3 053,3 038cm-1处的吸收峰,确定其为注胶处理的晕长石。     

月光石与无色透明拉长石的异同

目前市场上出现了一种无色透明、带有蓝色、橙黄色晕彩的拉长石,外观与月光石十分相似.本文综合了前人研究成果,总结出二者的异同,将这两种长石进行了对比.月光石与无色透明拉长石同属长石族矿物,但分别为两个不同的类质同相系列,在成分上有所区别.无色透明拉长石的折射率与比重比月光石要高;偏光显微镜下月光石呈负低突起,二轴晶负光性,解理少见,不发育双晶,而拉长石则呈正低突起,二轴晶正光性,可见两组交角近90°的解理,聚片双晶发育;月光石中K元素含量较多,而拉长石中Ca、Na的含量则更多;二者的XRD谱线及红外光谱谱线均有较大区别.因此可以通过折射率与比重测试、镜下观察、成分测试及谱学测试来区分月光石与无色透明拉长石.月光效应的形成是由光的散射作用所致,拉长石的晕彩色是因其内部的层状出溶结构对光的干涉所致.     

奈因斜长石饰面石材资源前景论析

矿山和能源部目前正在对奈因斜长石杂岩中的资源作调查。奈因地区的斜长石主要以拉长石为主,由于其漂亮的变彩效应,故有次等宝石之美称。为进一步评价这种斜长石的装饰效果,在奈因南部的3个勘探区,分别采集了含变彩拉长石5％～18％的试样作锯切和抛磨加工试验。堆积在太泊尔岛科林弗尔采石场的二级拉长石,是否可用来加工水磨石,预制混凝土板和环氧树脂板等,也正在进行评价。     

新疆阿尔泰可可托海伟晶岩矿床研究现状

可可托海矿床位于西伯利亚板块和哈萨克斯坦板块俯冲带附近,该矿床中3号脉最为典型,位于新疆阿尔泰富蕴县北东方向的可可托海镇,其结晶分异作用最完善,交代作用极为发育,带状构造明显,由边部至中心可分9个带为:Ⅰ.文象-变文象伟晶岩带;Ⅱ.糖粒状钠长石带;Ⅲ.块状微斜长石带;Ⅳ.白云母-石英带;Ⅴ.叶钠长石-锂辉石带;Ⅵ.石英-锂辉石带;Ⅶ.白云母-薄片状钠长石带;Ⅷ.锂云母-薄片状钠长石带;Ⅸ.核部块体石英和微斜长石带。     

宝石晕彩效应的成因机理综述

综合分析不同宝石晕彩成因机理的最新研究成果,结果表明:所有具有晕彩效应的宝石,其晕彩成因大多与其内部存在的周期性层状结构有关,且层状结构厚度也限定在一定的变化范围内,同时层状结构的形成途径及其厚度变化范围因宝石种属的不同而异。从光学原理上详细探讨了光的干涉和衍射的形成条件,对比了光在不同晕彩宝石内产生干涉或衍射的理论条件与其实际情况,分析了宝石晕彩效应产生的两种光学模型:薄膜干涉式晕彩不仅要求宝石内部结构层的厚度必须在一定的纳米范围内,而且要求结构层由两相组分出溶而成,即其化学成分、折射率和结构层厚度形成三位一体;而光栅式衍射晕彩则仅要求结构层排列规则、边缘狭窄,能使入射光的振幅或位相或两者同时产生周期性空间调制即可。     

缅甸条纹长石猫眼的宝石学特征研究

具有猫眼效应的宝石大致有20多种。长石族矿物是常见具有猫眼效应的宝石之一,其中以具钠长石律双晶的钠长石最为常见。但具有猫眼效应的条纹长石则报道很少。故本文就缅甸条纹长石猫眼的宝石学特征进行了较系统的研究,结果如下。 1、外观特征缅甸条纹长石猫眼外观上呈黑色、棕黑色或灰     

新发现的、罕见的猫眼宝石和星光宝石

描述了几个罕见的星光宝石和猫眼宝石. 产自巴西的淡蓝色托帕石显示出的猫眼效应是由扁平的管状孔洞引起的. 产自巴西的四射星光海蓝宝石有一个方向的星光是由平行c轴的管状孔洞引起, 另一组星光是由沿与c轴垂直方向排列的两相包裹体造成的. 一块产自巴西的碧玺-石英显示晕彩猫眼效应. 产自斯里兰卡的一块灰色正长月光石呈现出独特的猫眼效应和星光效应组合. 对造成这两种光学现象的缘由还不清楚. 来自俄罗斯的日光石具有清晰的猫眼效应, 是由钠长石-奥长石-正长石交互生长产生的条纹长石引起的. 四射星光的碧玺(双色锂电气石)有一个方向的星光是由管状孔洞引起, 另一方向的星光是由与c轴垂直的"发雏晶"引起的. 哈萨克斯坦菱锰矿具有的猫眼效应是由其类似于玛瑙的结构所致. 菱锰矿的四射星光效应是由两个方向的完全解理引起的.     

Reliable identification of grapevine rootstock varieties using RAPD PCR on woody samples

Since grapevine ( Vitis spp .) rootstock material is being traded increasingly as disbudded woody material a lack of distinctive morphological features on such material necessitates an alternative and reliable means of identification. Methods described here were developed for rapid and efficient extraction of DNA from woody samples rich in phenolic compounds and polysaccharides, and for subsequent identification of varieties by RAPD PCR. Using these methods, and with the application of only one selected RAPD primer, we were able to differentiate sixteen rootstock varieties, including the seven varieties most commonly used in Germany. Problems commonly encountered with reproducibility of RAPD patterns were avoided by choosing primers with a dinucleotide sequence and a high G/C content that allowed a rather high annealing temperature of 45°C. Methods described here should also be useful for other horticultural crops, especially those with woody tissues rich in phenolic compounds and polysaccharides.     

An internet compendium of analytical methods and spectroscopic information for monomers and additives used in food packaging plastics

An internet website (http://cpf.jrc.it/smt/) has been produced as a means of dissemination of methods of analysis and supporting spectroscopic information on monomers and additives used for food contact materials (principally packaging). The site which is aimed primarily at assisting food control laboratories in the European Union contains analytical information on monomers, starting substances and additives used in the manufacture of plastics materials. A searchable index is provided giving PM and CAS numbers for each of 255 substances. For each substance a data sheet gives regulatory information, chemical structures, physico-chemical information and background information on the use of the substance in particular plastics, and the food packaging applications. For monomers and starting substances (155 compounds) the infra-red and mass spectra are provided, and for additives (100 compounds); additionally proton NMR are available for about 50% of the entries. Where analytical methods have been developed for determining these substances as residual amounts in plastics or as trace amounts in food simulants these methods are also on the website. All information is provided in portable document file (PDF) format which means that high quality copies can be readily printed, using freely available Adobe Acrobat Reader software. The website will in future be maintained and up-dated by the European Commission's Joint Research Centre (JRC) as new substances are authorized for use by the European Commission (DG-ENTR formerly DGIII). Where analytical laboratories (food control or other) require reference substances these can be obtained free-ofcharge from a reference collection housed at the JRC and maintained in conjunction with this website compendium.     

Aroma characterization of various apricot varieties using headspace–solid phase microextraction combined with gas chromatography–mass spectrometry and gas chromatography–olfactometry

The characterization of the aromatic profile of several apricot cultivars with molecular tracers in order to obtain objective data concerning the aromatic quality of this fruit was undertaken using headspace–solid phase microextraction (HS–SPME). Six apricot cultivars were selected according to their organoleptic characteristics: Iranien, Orangered, Goldrich, Hargrand, Rouge du Roussillon and A4025. The aromatic intensity of these varieties measured by HS–SPME–Olfactometry were defined and classified according to the presence and the intensity of grassy, fruity and apricot like notes. In the six varieties, 23 common volatile compounds were identified by HS–SPME–GC–MS. Finally, 10 compounds, ethyl acetate, hexyl acetate, limonene, β-cyclocitral, γ-decalactone, 6-methyl-5-hepten-2-one, linalool, β-ionone, menthone and (E)-hexen-2-al were recognized by HS–SPME–GC–O as responsible of the aromatic notes involved in apricot aroma and considered as molecular tracers of apricot aromatic quality which could be utilized to discriminate apricot varieties.     

Tests of potential functional barriers for laminated multilayer food packages. Part I: Low molecular weight permeants

The advent of the functional barrier concept in food packaging has brought with it a requirement for fast tests of permeation through potential barrier materials. In such tests it would be convenient for both foodstuffs and materials below the functional barrier (sub-barrier materials) to be represented by standard simulants. By means of inverse gas chromatography, liquid paraffin spiked with appropriate permeants was considered as a potential simulant of sub-barrier materials based on polypropylene (PP) or similar polyolefins. Experiments were performed to characterize the kinetics of the permeation of low molecular weight model permeants (octene, toluene and isopropanol) from liquid paraffin, through a surrogate potential functional barrier (25 μm-thick oriented PP) into the food simulants olive oil and 3% (w/v) acetic acid. These permeation results were interpreted in terms of three permeation kinetic models regarding the solubility of a particular model permeant in the post-barrier medium (i.e. the food simulant). The results obtained justify the development and evaluation of liquid sub-barrier simulants that would allow flexible yet rigorous testing of new laminated multilayer packaging materials.     

Analysis of benzo[a]pyrene in spiked fatty foods by second derivative synchronous spectrofluorimetry after microwave-assisted treatment of samples

A simple, rapid and inexpensive method has been developed for the determination of benzo[a     

The development of reference materials for paralytic shellfish poisoning toxins in lyophilized mussel. II: Certification study

This paper describes the second part of a project undertaken to develop certified mussel reference materials for paralytic shellfish poisoning toxins. In the first part two interlaboratory studies were undertaken to investigate the performance of the analytical methodology for several PSP toxins, in particular saxitoxin and decarbamoyl-saxitoxin in lyophilized mussels, and to set criteria for the acceptance of results to be applied during the certification exercise. Fifteen laboratories participated in this certification study and were asked to measure saxitoxin and decarbamoyl-saxitoxin in rehydrated lyophilized mussel material and in a saxitoxin-enriched mussel material. The participants were allowed to use a method of their choice but with an extraction procedure to be strictly followed. The study included extra experiments to verify the detection limits for both saxitoxin and decarbamoyl-saxitoxin. Most participants (13 of 15) were able to meet all the criteria set for the certification study. Results for saxitoxin.2HCl yielded a certified mass fraction of <0.07 mg/kg in the rehydrated lyophilized mussels. Results obtained for decarbamoyl-saxitoxin.2HCl yielded a certified mass fraction of 1.59+/-0.20 mg/kg. The results for saxitoxin.2HCl in enriched blank mussel yielded a certified mass fraction of 0.48 +/- 0.06 mg/kg. These certified reference materials for paralytic shellfish poisoning toxins in lyophilized mussel material are the first available for laboratories to test their method for accuracy and performance.     

Announcing a new international peer-reviewed journal:Food Science and Human Wellness now accepting manuscript submission in English

<正>We are pleased to announce the launch of a new international peer-reviewed journal-Food Science and Human Wellness,ISSN 2213-4530,which is an open access journal,produced and hosted by Elsevier B.V.on behalf of Beijing Academy of Food Sciences.Food Science and Human Wellness is an international peer-reviewed English journal that provides a forum for the dissemination of the     

Chinese CTP Market

According to Printing and Printing Equipment Industries Association of China（PEIAC）＇s statistics to the plate manufucturer in China, in 2013, the actual offset plate production has reached 346 million square meters in China. Among them, the CTP production volume was 245 million square meters, up by 11% than that of last year; the total sales of the CTP plate was 239 million square meters, up by 13%.     

Preparatory Work of Print China 2015 is Going Smoothly

正Held at Guangdong Modern International Exhibition Center,Print China 2015 will cover 7exhibition halls,besides the original Hall No.3,4,5,6,7,the newly built F zone of Hall 3 will be used too.The total area will be140,000 square meters.Hall 3:Offset and large printing equipment,package printing equipment,post press