Uses of Gold in Jewellery

Abstract

Gold plays a dominant role in the jewellery market. This is to a large extent due to the intrinsic value of gold, its beauty and its unique resistance to tarnish and corrosion. In 1990 the amount of gold used in jewellery was about 2000 t worldwide, reaching about 75% of the total demand for gold. The demands on gold materials for jewellery, its applications in the form of bulk material for wrought and cast jewellery and as gold solutions for electrodeposition and electroforming as well as activities to introduce powder materials for the manufacture of jewellery are described. Today's conventional carat gold alloys are reviewed; coloured gold alloys based on the Au–Ag–Cu system, as well as the white gold alloys, based on Au–Ni or Au–Pd alloys. Additionally, the development of special gold alloys is mentioned, for instance that of a very high carat gold alloy, 990 gold–titanium.     

Synchrotron Radiation–Induced X‐Ray Fluorescence (SRXRF) Analyses Of The Bernstorf Gold

The gold finds from Bernstorf, in the Freising district of Bavaria, were discovered in 1998, in the area of a Bronze Age settlement. First analyses with X‐ray fluorescence (XRF) revealed gold of an unusually high purity grade, which was explained by the use of cementation techniques. A newer analysis with laser ablation inductively coupled plasma mass spectrometry (LA–ICP–MS) indicated an even higher purity. The analytical results were the starting point of an ongoing discussion. In this study, we re‐analysed 11 gold samples with synchrotron radiation–induced X‐ray fluorescence at the BAMline at BESSY. In a thorough analysis, different excitation and detection conditions were applied to confirm or disprove the previous results. It was shown that the purity of the gold from the specimen is higher than 99.9%. The main impurities are silver in a range between 20 and 200 μg g^?1 and copper between 1 and 10 μg g^?1. The results are in very good agreement with the LA–ICP–MS measurements and provide basic information for discussions about provenance, processing techniques or considerations of authenticity.     

The Hydrometallurgy of Gold Processing

Abstract

Gold has captured mankind's admiration for centuries as a medium of currency or exchange, for personal jewellery and for decorative and ornamental purposes. The mythical tale of Jason and the Golden Fleece may have its origins in the placer miners' technique of placing sheep's fleeces in sluices to capture gold flakes. This practice evolved around 1200bc and perhaps marked the start of the development of the 'art' and 'science' involved in recovering gold which existed at low levels in the Earth's crust and even in sea water. Since then gold processing technology has changed significantly to cope with the increasing scarcity of gold and the complexity of its ores. Today, 1 t of dirt has to be processed to recover a few grams of gold. This difficulty has not stopped mankind from looking for this metal, which is considered both precious and evil by Eastern and Western civilisations. The scarcer the metal becomes, the more sophisticated must be the exploration technology that is developed to look for gold. Likewise, processing techniques have been continually improved and modified to cope with the increasing complexity of the ores from which gold must be recovered.     

Never Judge A Gold Object by Its Surface Analysis: A Study of Surface Phenomena in a Selection of Gold Objects From the Staffordshire Hoard

With the introduction of commercially available handheld XRF analysers, there is a growing problem that the results, simply taken at face value, are regarded as representative of the bulk gold alloys of the objects analysed in museums and used for treasure analysis. It is well known that surface analysis is problematic, and the aim of this study was to test whether non‐destructive surface analysis could be useful in grouping the very large numbers of fragmentary pieces in the Anglo‐Saxon Staffordshire Hoard. Surface and subsurface analyses of 16 objects from the Hoard were carried out by X‐ray fluorescence (XRF) and scanning electron microscopy with energy‐dispersive X‐ray analysis (SEM–EDX). The results indicate that there are significant but inconsistent levels of enrichment of the gold at the surface of many of these objects, due to the loss of both copper and silver. The significant loss of silver (up to 50% relative in some cases) suggests that some form of deliberately induced depletion gilding was carried out during manufacture to remove both silver and copper from the surface. In three cases, an increase in silver at the surface compared to the core metal was detected: this might tentatively be explained by redeposition from contact with silver objects during burial. These results have clear implications for the reliability and interpretation of surface analysis data of gold alloys from this period.     

The Economics of Gold

Abstract

From day to day or month to month, the price of gold can swing violently. But over much longer time spans, gold holds its real value rather well. This paradox is explored in this paper; it is explained by the notion that a well informed market should overreact to news about the fundamentals governing its long run value; and then, in the absence of further shocks, the price and stock of gold in use should tend to drift in opposite directions until the long run point of balance is attained. The paper also investigates other issues concerning gold, including the suggestion that paper currency should be backed by gold.     

青海卡约文化出土的金器

卡约文化是分布在青海地区青铜时代的考古学文化,除发现陶、石、骨、角、牙、料器等类文物外,还发现了一批主要用于装饰的金器。这批金器从制作到用途,反映了青藏高原东北部古羌民族的重要文化特色。作为我国目前发现的最早黄金制品之一,卡约文化金器代表的是这一时段金属冶炼和制作技术的水平,也为我们探讨黄金的原始功用提供了重要线索。     

从契丹墓葬金银器看古代北方草原金饰艺术

世界上许多民族都把金银器当作富贵和寓意天长地久的珍贵物品,从埃及法老到印度国王,从罗马教皇到中国皇帝,都在生前和死后大量使用、随葬金银器。内蒙古古代北方草原民族,也十分喜欢用金银器作为装饰品,比之其他民族有过之而无不及。     

Gold Chemistry is Different

Abstract

The attractive properties of gold have long been taken for granted without any questioning of the basic chemistry that lies behind them. Today, chemists are beginning to find the reasons for gold's unique position among the family of elements. After a general introduction to gold chemicals and a review of some of the element's unusual facets, the author, who has contributed much himself to this research, explains that only through a consideration of relativistic effects has a deeper understanding of the chemistry of gold emerged. These theoretical advances have led to the preparation of a multitude of novel gold compounds characterised by clusters of gold atoms which can incorporate carbon and nitrogen atoms. In the light of these modern concepts of bonding and structure, the chemistry of gold is now a subject of research in many laboratories and its literature has exploded.     

Evidence of Soldering Technology on Pre‐Columbian Gold Pendants from Western and North‐Western Colombia

Microscopic examination and analysis (metallography, X‐radiography, SEM–EDS, pXRF and μ‐XRF) of a group of stylistically linked gold alloy pendants from western and north‐western Colombia confirms the use of a highly unusual manufacturing technique for the region. While the Darién pendants were made using lost‐wax casting by a diverse group of cultures from southern Colombia through Costa Rica, only one subset of pendants produced in the Gran‐Zenú region (the Caribbean lowlands of northern Colombia) and the Chocó region (the Pacific area of western Colombia) in the Early Period (ad 0–900) was found to be manufactured by hammering of gold sheet and fine wires followed by hard soldering of components to produce true filigree. Similarities in features between the stylistically related cast and hammered pendants suggest that the hammered pendants may have served as a prototype for the cast versions. Other possible instances of hard soldering in the region are also presented.     

The Design of Gold Jewellery Stimulation and Promotion by the World Gold Council

Abstract

As with any work of art or industrial product, good design of jewellery is essential if it is to appeal to its owner. In the field of gold jewellery, the World Gold Council is playing a leading role and its efforts are here reviewed by commenting on the taste in British and Continental design of gold jewellery. Consumer preference, whether organic, symbolic or elementary jewellery is preferred, and the growth of the market are here discussed.     

Geological setting, nature of ore fluids and sulphur isotope geochemistry of the Fu Ning Carlin-type gold deposits, Yunnan Province, China

Carlin‐type gold deposits in southern China are present in Palaeozoic to Mesozoic siliciclastic and carbonate rocks. The border region of Yunnan, Guizhou and Guangxi Provinces contains gold deposits on the south‐western margin of the Pre‐Cambrian South China Craton in south‐eastern Yunnan Province. The Fu Ning gold deposits host epigenetic, micron‐sized disseminated gold in: (i) Middle Devonian (D₁p) black carbonaceous mudstone at the Kuzhubao gold deposit and (ii) fault breccia zones at the contact between Triassic gabbro (β ) and the Devonian mudstone (D₁p) at the Bashishan gold deposit. The deposits are associated with zones of intense deformation with enhanced permeability and porosity that focused hydrothermal fluid flow, especially where low‐angle N‐S striking thrust faults are cut by NW striking strike‐slip and/or NE striking normal faults. Major sulphide ore minerals in the Fu Ning gold deposits are pyrite, arsenopyrite, arsenic‐rich pyrite, stibnite and minor iron‐poor sphalerite. Gangue minerals are quartz, sericite, calcite, ankerite and chlorite. Hypogene ore grades range from 1 to 7 g t^?1 Au and up to 18 g t^?1 Au at the Kuzhubao gold deposit and are generally less than 3 g t^?1 Au at the Bashishan gold deposit. Sub‐microscopic gold mineralization is associated with finely disseminated arsenic‐rich pyrite in the Stage III mineral assemblage. Two types of primary fluid inclusions have been recorded: Type I liquid–vapour inclusions with moderate‐to‐high liquid/vapour ratios, and Type II inclusions containing moderate liquid/vapour ratios with CO₂ as determined from laser Raman analysis. Temperature of homogenization (T_h) data collected from these primary fluid inclusions in gold‐ore Stage III quartz ranged from 180 to 275°C at the Kuzhubao gold deposit and 210 to 330°C at the Bashishan gold deposit. Salinity results indicate that there were possibly two fluids present during gold deposition, including: (i) an early fluid with 0.8–6.5 wt.% NaCl equivalent, similar to salinity in shear‐zone‐hosted gold deposits with metamorphic derived fluids; and (ii) a late fluid with 11.8–13.4 wt.% NaCl equivalent, indicating possible derivation from connate waters and/or brine sources. CO₂ and trace CH₄ were only detected by laser Raman spectrometry in gold‐ore‐stage primary fluid inclusions. Results of sulphur isotope studies showed that δ³⁴S values for pyrite and arsenopyrite associated with gold‐ore mineralization during Stage III at the Kuzhubao and Bashishan gold deposits are isotopically similar and moderately heavy with a range from +9 to +15 per mil, and also fall into the range of δ³⁴S values reported for Carlin‐type gold deposits. Sulphur isotopes suggest that the Fu Ning gold deposits were formed from connate waters and/or basinal brines. Fluid geochemistry data from the Fu Ning gold deposits suggest a Carlin‐type genetic model, involving fluid mixing between: (i) deep CO₂‐rich metamorphic fluids, (ii) moderately saline, reduced connate waters and/or basinal brines; and (iii) evolved meteoric waters.     

Globalization,Recession and the Internationalization of Industrial Districts: Experiences from the Italian Gold Jewellery Industry

Abstract

Globalization and the recent recession crisis are significantly challenging Italian industrial districts (IDs), leading to deep transformations in their internationalization, innovation and organization strategies. With our empirical focus on a single industry (gold jewellery) and a specific country (Italy) and through the theoretical lenses of the global value chain (GVC) approach, the evidence in this article sheds light on the differences in how three IDs within Italy's gold jewellery sector (Valenza Po, Arezzo and Vicenza) compete in the global arena. Our comparative analysis reveals striking differences among these districts with regard to their upstream and downstream internationalization strategies in response to two industry shocks: increasing global competition in the early 2000s and the world economic recession of 2008–2009. Our explanation for the varied gold jewellery district responses to these two global crises involves both internal and external factors: (1) structural differences between the three IDs; (2) distinct business strategies; and (3) how these districts are linked to the gold jewellery GVC.     

徐州楚王墓出土金银器大观

金和银两种金属,由于他们的结构密实,外表艳丽而舒润,延展性强,韧性好,便于操作,自古就受到人们的青睐,为人们所钟爱。常用它来制作货贝及器皿和饰品。     

The Monetary Role of Gold

Abstract

After a brief introduction to the role of gold as a monetary agent in history, the classical gold standard and the Bretton Woods agreement and its failure are discussed. Since then the price of gold has fluctuated widely and has only recently steadied. The monetary role of gold at present is then considered. Gold stocks, their supply and demand and various economic factors playing a role in price formation are mentioned in detail. Inflation and countercyclicality in relation to the Morgan Stanley Index of World Equities are the final subjects of this review.     

The Production of Thin‐Walled Jointless Gold Beads from the Maykop Culture Megalithic Tomb of the Early Bronze Age at Tsarskaya in the North Caucasus: Results of Analytical and Experimental Research

This study, the first of this kind, reconstructs the technical chaîne operatoire of thin‐walled jointless gold bead production in the Maykop culture on the basis of trace‐wear analysis, experimental research and comparative analysis, using gold beads from the Early Bronze Age dolmen (c. 3200–2900 bc ) in kurgan 2 at Tsarskaya (discovered in 1898). The results of the study demonstrate that such beads were produced from a perforated disc‐shaped blank by pressure (with intermittent annealing) within a hemispherical depression in a shaping block (presumably made from stone or bone) and subsequent abrasive treatment of the surface. Most probably, this technique was a regional expression of Near Eastern jewellery traditions that emerged within the urbanized centres of Upper Mesopotamia in the early fourth millennium bc and spread out, through the Caucasus, into the southern boundaries of the Eurasian steppe.     

金玉同盟——东周金器和玉器之装饰风格与角色演变

除了延续自前代的风格传统与工艺技术外,东周玉器与源自于他类材质器物的启发关系尤其密切,其中金器扮演了关键性的角色。东周金器对玉器装饰风格的影响,主要表现在纹饰布局、纹饰母题以及追求浮雕的空间表现等几个方面。此时玉器和金器在风格上的相互转换与兴替消长,不仅导致金玉材质间的相互置换,更重要的是,它们的装饰形式也因应被模仿对象的材质特性而改头换面,并且发展出新的审美价值和象征意蕴。     

楚金币的发现与研究

本文概述了楚国金币的发现情况,对楚金币的种类、形制、印记、重量与刻文诸问题加以探讨,对楚金币出土情况进行剖析,认为,楚金币是流通中的秤量货币,它与铜贝是主币与辅币的关系;并对楚金币的币材产地、冶炼技术与铸造年代等进行研究。     

Simulation of adsorption of gold nanoparticles carried by gas ascending from the Earth’s interior in alluvial cover of the middle–lower reaches of the Yangtze River

The adsorption onto other minerals of charged gold nanoparticles, carried by gas ascending from the Earth’s interior, is an important component of their transport and deposition in surficial cover such as alluvial, aeolian, and glacial sediments. To simulate the adsorption of these particles, an experiment was conducted in which a flow of air that contained gold nanoparticles was passed upward through a sample of alluvium from the middle–lower reaches of the Yangtze River. These experiments showed that gold nanoparticles are adsorbed on kaolinite, halloysite, goethite, and hematite in the alluvial cover. Both the gold nanoparticles and minerals (i.e., kaolinite, halloysite, goethite, and hematite) carry surface charges that provide them with excellent adsorption properties. This study showed that the specific mineral composition of surficial alluvial cover affects the concentration of gold nanoparticles in the ascending gas. This phenomenon may plausibly be used in exploration for concealed gold, copper–gold, and silver–gold deposits in areas of thick alluvial cover. Geofluids (2010) 10 , 438–446     

明定陵出土宫廷御用金器（下）

四.药具在定陵出土文物中有一对带柄罐（图30）。分别出自万历帝棺内东端的南北两侧。形制、大小基本相同。铭文标明二者仅重量只差一钱。小直口,深腹,平底。腹上部一侧附带圆銎,銎内安木柄贯钉加固。盖为弧面阶梯形,圆钮,子口,素面。底部用双线刻铭文一周：“大明万历年御用监造八成五色金重二十二两四钱”,