Gems & Gemology最新文献_第7页

Geographic Origin Determination of Ruby 红宝石的地理来源测定

IF 2.6 3区地球科学

Gems & Gemology Pub Date : 2019-02-01 DOI: 10.5741/gems.55.4.580

Aaron C. Palke, Sudarat Saeseaw, Nathan D. Renfro, Ziyin Sun, S. McClure

引用次数: 13

Geographic Origin Determination of Blue Sapphire 蓝蓝宝石的地理起源测定

IF 2.6 3区地球科学

Gems & Gemology Pub Date : 2019-02-01 DOI: 10.5741/gems.55.4.536

Aaron C. Palke, Sudarat Saeseaw, Nathan D. Renfro, Ziyin Sun, S. McClure

引用次数: 19

Corundum with Spinel Corona from the Tan Huong-Truc Lau Area in Northern Vietnam 越南北部Tan Huong Truc Lau地区带尖晶石电晕的刚玉

IF 2.6 3区地球科学

Gems & Gemology Pub Date : 2019-02-01 DOI: 10.5741/GEMS.54.4.404

Nguyễn Ngọc Khôi, C. Hauzenberger, C. Sutthirat, D. A. Tuan, T. Häger, N. Nam

引用次数: 2

The History and Reconstruction of the Amber Room 琥珀屋的历史与重建

IF 2.6 3区地球科学

Gems & Gemology Pub Date : 2019-02-01 DOI: 10.5741/gems.54.4.393

R. Shor

引用次数: 2

The Color Origin of Gem Diaspore: Correlation to Corundum 宝石二孢子的颜色起源：与刚玉的关系

IF 2.6 3区地球科学

Gems & Gemology Pub Date : 2019-02-01 DOI: 10.5741/GEMS.54.2.394

Chen Shen, Ren Lu

{"title":"The Color Origin of Gem Diaspore: Correlation to Corundum","authors":"Chen Shen, Ren Lu","doi":"10.5741/GEMS.54.2.394","DOIUrl":"https://doi.org/10.5741/GEMS.54.2.394","url":null,"abstract":"position in the gem market due to its rarity, striking pleochroism, and color-change phenomenon (figure 1). The material’s value depends on these factors. A clear understanding of color origin offers considerable benefits for gemological testing, cutting, and even valuation of gem diaspore. By replacing the major elements in definite structural units through isomorphous substitution, trace elements play an important role in the color of gemstones. The AlO6 octahedra is a significant structural unit that produces color when different trace elements substitute for Al. For example, Cr3+ substitutes for Al3+ in the AlO6 octahedra in jadeite and spinel, causing green and red color (Lu, 2012; Malsy, 2012), while the substitution of Fe3+ for Al3+ in sapphire produces yellow color (Emmett et al., 2003). Diaspore and corundum have a similar chemical composition and crystal structure (see figure 2). Diaspore, with the chemical formula AlO(OH), belongs to the orthorhombic space group 2/m 2/m 2/m (Hill, 1979); corundum, with the chemical formula Al2O3, belongs to the trigonal space group 3̅ 2/m (Lewis et al., 1982). The crystal structure of diaspore consists of AlO4(OH)2 octahedra, whereas the corundum crystal structure consists of AlO6 octahedra (Hill, 1979; Lewis et al., 1982). Both types of crystals are composed solely of octahedral units. In addition, the diaspore structure is able to convert to corundum structure through dehydration (Iwai et al., 1973). Due to their closely related crystallographic structure and chemical composition,","PeriodicalId":12600,"journal":{"name":"Gems & Gemology","volume":" ","pages":""},"PeriodicalIF":2.6,"publicationDate":"2019-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45452021","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Geology of Corundum and Emerald Gem Deposits: A Review 刚玉和祖母绿矿床地质研究进展

IF 2.6 3区地球科学

Gems & Gemology Pub Date : 2019-02-01 DOI: 10.5741/gems.55.4.464

G. Giuliani, L. Groat

引用次数: 17

Inclusions in Natural, Synthetic, and Treated Diamond 天然、合成和处理过的钻石中的内含物

IF 2.6 3区地球科学

Gems & Gemology Pub Date : 2019-02-01 DOI: 10.5741/gems.54.4.428

Nathan D. Renfro, John I. Koivula, J. Muyal, S. McClure, Kevin Schumacher, J. Shigley

引用次数: 3

A Review of Analytical Methods Used in Geographic Origin Determination of Gemstones 宝石地理成因分析方法综述

IF 2.6 3区地球科学

Gems & Gemology Pub Date : 2019-02-01 DOI: 10.5741/gems.55.4.512

L. Groat, G. Giuliani, J. Stone‐Sundberg, Ziyin Sun, Nathan D. Renfro, Aaron C. Palke

{"title":"A Review of Analytical Methods Used in Geographic Origin Determination of Gemstones","authors":"L. Groat, G. Giuliani, J. Stone‐Sundberg, Ziyin Sun, Nathan D. Renfro, Aaron C. Palke","doi":"10.5741/gems.55.4.512","DOIUrl":"https://doi.org/10.5741/gems.55.4.512","url":null,"abstract":"GEMS & GEMOLOGY WINTER 2019 In gemology, “origin” refers to the geographic locality of a gemstone deposit (Hänni, 1994). Origin determination of colored gemstones began with Gübelin and SSEF (both in Switzerland) in the 1950s and with AGL (New York) in 1977 (Schwarz, 2015). Origin determination is of increasing importance in today’s market, and for many gems this information is considered either a value-adding factor or a positive for the salability of a gemstone (Hainschwang and Notari, 2015). Origin determination is often possible because there is a close relationship between the environment of crystallization, especially the mineralogical and chemical composition of the host rock, and the properties of the gemstones that can be studied in the lab, often using sophisticated equipment (Hänni, 1994). In this paper we review the analytical techniques (figure 1) commonly used to characterize gem materials, with a specific focus on geographic origin determination. We also review the physical and chemical properties of corundum and emerald, which have the greatest demand for origin determination. Finally, we provide examples of origin determination of corundum and emerald from the literature to illustrate how these analytical methods are applied to the problem of establishing origin.","PeriodicalId":12600,"journal":{"name":"Gems & Gemology","volume":" ","pages":""},"PeriodicalIF":2.6,"publicationDate":"2019-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47695273","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 18

Geographic Origin Determination of Emerald 翡翠的地理成因测定

IF 2.6 3区地球科学

Gems & Gemology Pub Date : 2019-02-01 DOI: 10.5741/gems.55.4.614

Sudarat Saeseaw, Nathan D. Renfro, Aaron C. Palke, Ziyin Sun, S. McClure

{"title":"Geographic Origin Determination of Emerald","authors":"Sudarat Saeseaw, Nathan D. Renfro, Aaron C. Palke, Ziyin Sun, S. McClure","doi":"10.5741/gems.55.4.614","DOIUrl":"https://doi.org/10.5741/gems.55.4.614","url":null,"abstract":"GEMS & GEMOLOGY WINTER 2019 When the Spanish conquistadors first brought Colombian emeralds (figures 1 and 2) onto the international market, they became a global sensation in their day. Emeralds from Central Asia and Egypt were known at the time, but the world had likely never seen emeralds of such high quality and size. Traders soon developed distribution channels that brought the Colombian material all the way from the royal courts in Europe to the powerful Moguls of India (Giuliani et al., 2000). The nineteenth and twentieth centuries saw all of this change as new mines sprang up around the world to challenge the famed Colombian emeralds. Most notable in terms of high-quality production were Brazil, Russia, and Zambia, but smaller deposits have been uncovered in Madagascar and Ethiopia and elsewhere. As the market has evolved alongside these developments, geographic origin has come to be an important factor for fine-quality emeralds. The demand for emerald origin determination was initially driven by the proliferation of sources. However, this expansion and diversification of emerald sources has also complicated origin determination. As the number of sources grows, so does the overlap in their characteristics. The following sections will detail the specific criteria used in the laboratory at GIA to make geographic origin conclusions for emeralds, as well as potential areas of overlap and how these are dealt with.","PeriodicalId":12600,"journal":{"name":"Gems & Gemology","volume":" ","pages":""},"PeriodicalIF":2.6,"publicationDate":"2019-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45730154","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 20

Geographic Origin Determination of Paraiba Tourmaline Paraiba碧玺的地理来源测定

IF 2.6 3区地球科学

Gems & Gemology Pub Date : 2019-02-01 DOI: 10.5741/gems.55.4.648

Yusuke Katsurada, Ziyin Sun, C. Breeding, B. Dutrow

{"title":"Geographic Origin Determination of Paraiba Tourmaline","authors":"Yusuke Katsurada, Ziyin Sun, C. Breeding, B. Dutrow","doi":"10.5741/gems.55.4.648","DOIUrl":"https://doi.org/10.5741/gems.55.4.648","url":null,"abstract":"GEMS & GEMOLOGY WINTER 2019 Copper-bearing gem tourmaline—recognizable by its vivid neon blue to green color—has been one of the most popular colored gemstones on the market for the nearly three decades since its debut (figures 1 and 2). It was first discovered in the state of Paraíba in northeastern Brazil in the late 1980s, and subsequently found in the neighboring state of Rio Grande do Norte (Fritsch et al., 1990; Shigley et al., 2001; Furuya, 2007). These gems became known as Paraíba tourmalines after the locality of their discovery. In the early twenty-first century, similarly colored gem-quality tourmalines were discovered in Nigeria and Mozambique (figures 3 and 4; Smith et al., 2001; Abduriyim and Kitawaki, 2005). In the gem market, Brazilian Paraíba tourmalines are typically more highly valued than their African counterparts. While top-quality Brazilian Paraíba tourmalines tend to have more intense color, there is significant overlap in the color range for all localities. Additionally, standard gemological tests cannot definitively separate stones from these three localities. As a result, there is market demand for gemological laboratories to offer origin determination for copper-bearing tourmalines. The most recent Laboratory Manual Harmonisation Committee (LMHC) definition of “Paraíba” tourmaline is “a blue (electric blue, neon blue, violet blue), bluish green to greenish blue, green (or yellowish green) tourmaline, of medium-light to high saturation and tone (relative to this variety of tour-","PeriodicalId":12600,"journal":{"name":"Gems & Gemology","volume":" ","pages":""},"PeriodicalIF":2.6,"publicationDate":"2019-02-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42513242","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"地球科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3