JOYce Posted May 28, 2004 Report Share Posted May 28, 2004 Some Golden Facts (A bit Lenghty But Reading a worth especially for Ladies ) ::::::Yawn::::: GOLD JEWELLERY From the first discoveries of gold in ancient times, its beauty and the ease with which it could be worked inspired craftsmen to create it into ornaments, not just for adornment, but as symbols of wealth and power. The skills of the goldsmith from ancient Egypt to Benvenuto Cellini or Carl Faberge still amaze us. As Pihder wrote nearly 2,500 years ago, "Gold is the child of Zeus, neither moth nor rust devoureth it". Today, gold jewellery is more a mass- market product, although in many countries still treasured as a basic form of saving. jewellery fabrication is the crucial cornerstone of the gold market, annually consuming all gold that is newly mined. Pure gold is used in those parts of the world where jewellery is purchased as much for in- vestment as it is for adornment, but it tends to be vulnerable to scratching. Elsewhere, it is usually mixed, or alloyed, with other metals. Not only do they harden it, but influence the colour; white shades are achieved by alloying gold with silver, nickel or palladium; red alloys contain mainly copper. A harder alloy is made by adding nickel or a tiny percentage of titanium. The proportion of gold in jewellery is measured on the carat (or karat) scale. The word carat comes from the carob seed, which was originally used to balance scales in Oriental bazaars. Pure gold is designated 24 carat, which compares with the "fineness" by which bar gold is defined. Pure gold Gold alloys Caratage Fineness % Gold 24 1000 100 22 916.7 91.67 18 750 75 14 583.3 58.3 10 416.7 41.67 9 375 37.5 The most widely used alloys for jewellery in Europe are 18 and 14 carat, although 9 carat is popular in Britain. Portugal has a unique designation of 19.2 carats. In the United States 14 carat predominates, with some 10 carat. In the Middle East, India and South East Asia, jewellery is traditionally 22 carat (sometimes even 23 carat). In China, Hong Kong and some other parts of Asia, "chuk kam" or pure gold jewellery of 990 fineness (almost 24 carat) is popular. In many countries the law requires that every item of gold jewellery is clearly stamped with its caratage. This is often controlled through hallmarking, a system which originated in London at Goldsmiths' Hall in the 14th century. Today it is compulsory in such countries as Britain, France, the Netherlands, Morocco, Egypt, and Bahrain. Where there is no compulsory marking manufacturers themselves usually stamp the jewellery both with their own individual identifying mark and the caratage or fineness. The European Commission wants to introduce a common system for guaranteeing standards of fineness within member countries of the European Community. Three strictly supervised systems are possible; either I) Hall- marking, 2) Quality control, according to the European norm on quality (EN 29000), or 3) Certificate of conformity by manufacturers, control- led by an independent third party.Until recently the earliest known gold jewellery was believed to date from the Sumer civilisation, which inhabited what is now southern Iraq around 3000 BC. Recent discoveries suggest however that goldsmithing first began on the shores of the Black Sea, in the land that is today Bulgaria (for more information follow this link to the Pointe-Ã -CalliÃ¨re museum of MontrÃ©al http://www.pacmusee.qc.ca/an/expos/varna/histoire.html. Articles displaying various techniques such as repousse, chain- making, alloying and casting have been found in ancient Egyptian tombs, with the best known examples coming from the treasures of King Tutankhamun who died in 1352 BC. The Minoans on Crete produced the first known cable chain, still very popular today, and the Etruscans in Italy had developed granulation, whereby items are decorated with tiny granules of gold, by the 7th century BC. Italy has remained at the forefront of the gold jewellery industry. The Italian Renaissance coincided with the discoveries of the New World sources of gold, and wealthy Italian patrons encouraged goldsmiths as they did painters and sculptors. The Spanish acquisition of South American gold, however, was achieved at the expense of the ancient heritage of Pre-Columbian goldsmiths. These craftsmen were producing exquisite items as early as 1200 BC and their art reached its zenith during the Chimu civilisation from the 12th to the I5th centuries AD, halted only by the mass looting and slaughter by the "conquistadors". picture: Historically, gold was a rare metal, afforded only by the wealthy. But the gold rushes to California and Australia in the mid- 19th century ushered in a new dimension of gold supply. They coincided, too, with the development of machinery for making chain and other articles and of a much wider consumer market. In the 20th century gold jewellery has come within the pocket of most people.The way ahead was pointed by Italy, which has become jewellery manufacturer to the world, using over 400 tonnes of gold annually, more than two- thirds of it for export. Factories often housing several hundred ma- chines that "knit" gold wire into chain flourish in the towns of Arezzo, Bassano del Grappa and Vicenza. Important new centres emerged in the early 1990s, notably in Hong Kong, Singapore, Malaysia and Thailand, catering particularly for the rapidly growing market for chukka am (pure gold) jewellery in China, which requires several hundred tonnes a year. In Japan jewellery fabrication for the domestic market has become a major industry, using around 100 tonnes a year. Attitudes to jewellery still vary. In the industrial countries gold jewellery is primarily a fashion item. But in the Middle East and much of Asia gold ornaments are seen equally as investment; 22 carat articles are bought on a low mark-up of only 10-20 per cent over the gold price of the day, and may be traded in at a profit if the price rises or, more often, for new articles. The importance of jewellery to the gold mining industry cannot be under-estimated. Between 1970 and 1992 around 65 per cent of all gold available to the market was used in jewellery, and from the late 1980's into the 1990's, it absorbed much of the rise in production. Since 1991 over 2,000 tonnes of gold has been used annually. The continuing success of the mining industry is inextricably linked with the fortunes of the jewellery trade. The Golden Rules With increasing interest everywhere in gold jewellery, it is now available in more designs and patterns than ever before. While you might choose to have several designs or styles, it is important to remember that every gold ornament needs to be cared for in a special way. Storage solutions When you buy gold jewellery, make sure that it is given to you in a box with a satin or velvet lining. Gold ornaments should not be kept in pouches, because this will cause scratching and wearing away of gold when the gold pieces brush against each other. This is even more likely if the ornament is studded with diamonds or other hard gemstones. Ideally, two different gold ornaments should not be kept in the same box. Wrapping smaller items of jewellery individually in tissue paper before keeping them in the box safeguards them from scratches. Keep it clean... It is best to use a soft cleaning cloth, chamois leather or synthetic chamois to clean your jewellery. A good gold cleaning liquid is also useful for maintaining the shining glory of your gold jewellery. When cleaning your jewellery, always use soft, non-abrasive material. A good cleaning liquid may be used for intricate jewellery with delicate links, which a cloth may not reach. Once in a while, gold ornaments should be cleaned by dropping them into boiling water in which a pinch of sodium barcarbonate has been added, for just half a minute. Drop one piece of jewellery at a time and remove it. Then wipe it immediately with a soft cloth. Family Heirlooms Always handle family heirlooms and antique jewellery very delicately. Wipe them with a soft cloth, or get them cleaned by a reliable jeweller. Never jumble jewels in very small containers. Remember also to keep your genuine gold jewellery away from costume jewellery. Always keep jewellery of different karatages separately. So, now that you know exactly how to make sure that your gold stays as brilliant and radiant as on the day that you got it; just follow these golden rules of gold care. Safety for your JewelleryIt is very important to insure your gold jewellery, so that you can recover its value if it is ever misplaced or stolen. Getting a small safe installed is a good idea if you choose to keep your expensive gold jewellery at home. It is also advisable to maintain a list of everything that you put in and take out of your safe. Your jeweller's guarantee card should also be kept safely with your jewellery, inside the safe. For added security, it is best to deposit your jewellery in the safe deposit vault of a bank.One intelligent thing to do is to photograph your jewellery, especially when you are wearing it. This is an inexpensive yet effective way ensure that your jewellery is traceable, should you ever lose it. This is also vital evidence for those helping you to locate your lost or stolen jewellery. Remember to inform the police immediately if your jewellery is ever stolen. Tips on buying goldKaratage is an important factor in buying gold jewellery. It indicates the percentage of real gold in any piece of jewellery. In most cases, the karatage of the piece of jewellery is mentioned on it, apart from the hallmark of the jeweller. This is genuine proof that it is indeed real gold.24 karat gold is pure. It is soft, almost flexible and easy to break. That is why it is not always used in the making of modern jewellery which features delicate designs. Other metals like silver, copper, nickel or zinc are added to gold in small quantities to make it workable, durable and even colourful.In choosing gold jewellery, the primary aim should be to build up a collection of the first five essential pieces, which are: necklace, bracelets, long earrings, big round earrings and different pendants. Always remember to choose gold jewellery for your collection with utmost care; it has to reflect your taste.While care must be taken to pick up the karatage you desire from a good jeweller, you should be equally certain that the jewellery you choose will look good on you. If you are buying a new style in gold jewellery for the first time, it is advisable to get someone who understands gold jewellery fashions and trends, to go with you. Most times, the counter staff will satisfactory provide all the details you need to know.Many other factors also need to be considered when deciding on what gold jewellery to buy. The shape of your face, your height, the colour of your skin, your complexion, your hairstyle, the slenderness and length of your neck, the slenderness of the limbs, the kinds of makeup you wear, your overall personality and even your taste in dress should be carefully considered, if you want your gold jewellery to really look beautiful on you. Popular Gold KaratagesGold jewellery is available in a variety of karatages. The preferences for a certain karatage of gold is usually based on cultural, regional or traditional factors. For instance, 22 karat gold is predominantly used in India; while 21 karat gold is preferred by Arabs. Most Europeans prefer 18 karat gold. 24 karat gold, which is considered the purest gold available, is usually used as a mode of investment or exchange. The Caratage (Karatage) System For Gold Jewellery Gold jewellery/ jewelry is usually described in terms of caratage (karatage), which is an indication of its gold content, for example 18 carat or 18K. Alternatively, the gold content can be described in terms of â€˜finenessâ€™, which is the gold content expressed in parts per thousand, for example 750 (which is 18 carat or 75.0% gold). Since the price paid by the purchaser for gold jewellery is based on the amount of gold in it, it is important for the consumer to know how many carats (in USA â€“ karats) of gold there is in the piece. Most jewellery worldwide is marked with the caratage or fineness. This may be part of a Hallmark on the jewellery (see Assaying & Hallmarking for the definition of a mark and hallmark).Pure gold (â€˜fine goldâ€™) is 24 carats (karats) and so 24 carats is theoretically 100% gold. In Chinese, it is also known as â€œChuk Kamâ€, meaning â€˜pure goldâ€™ and is defined as 99.0% gold minimum. Thus, there is a 1.0% negative tolerance allowed in this case. The Caratage SystemAny caratage value lower than 24 is a measure of how much gold there is in the jewellery gold alloy. Thus 18 ct is 18/24ths of 100% gold = 75.0% gold. In fineness terms, this is described as 750 fineness, i.e. 750 parts of gold per thousand parts. The table below gives the various caratages and their equivalent gold content in percent or in fineness terms as recognised by international standards. This is not always exactly the mathematical value! For example, 22 carat is mathematically 22/24ths x 100 = 91.666% but the accepted international standard is 91.60%Definition of Caratage in gold content for recognised international standardsCarats/Karats Fineness, â€° Gold content, % Comments 24 999 99.9 - 24 990 99.0 Minimum allowed 22 916 91.6 Indian subcontinent 21 875 87.5 Arabic countries (19.2) 800 80.0 Standard in Portugal 18 750 75.0 Standard caratage 14 585 58.5 583/58.3% in USA 10 417 41.7 Minimum in USA 9 375 37.5 U.K. standard 8 333 33.3 Minimum Germany Many countries only allow certain caratages of gold jewellery to be sold. For example, in the United Kingdom, one can make and sell 9, 14 ,18 and 22 carat gold jewellery but not 12 carat gold as the latter is not a recognised caratage standard by law. In some countries, jewellery lower than 12 carats (50% gold or 500 fineness) cannot be described as gold.The advantage of making jewellery in caratages lower than 24 ct, apart from price, is the wide range of colour that can be achieved, from socalled green, pale yellow, yellow, rose/pink to red as well as white, depending on the balance of other alloying metals used. The lower the caratage, the wider range of colour is possible (see Colours of Gold). Additionally, properties such as strength and hardness are improved over pure gold, leading to improved wear and scratch resistance and less liable to distortion and damage.The caratages of jewellery allowed by law varies from country to country (see below for link to Table of national fineness standards). In the U.K., for example, the following caratages are allowed: 9 (375), 14 (585), 18 (750), 22 (916), and 24 (990 and 999). In many countries, a large range of caratages is legally allowed but only a few are in common use. The dominant caratage also varies as shown in the next table:Typical Caratages of Gold Jewellery Region Typical Caratage (fineness) Oriental East (China, Hong Kong, Taiwan) 24 carat 'Chuk Kam' (99.0% min) India & subcontinent 22 carat (91.6%) Arabic countries in Gulf region 21 carat (87.5%) Europe - Southern */ Mediterranean 18 carat (75.0%) Europe - Northern, USA, etc** 8-18 carat (33.3 - 75.0%) * Portugal - 19.2 carat (80.0%) ** For example, Germany - 14 ct with 8 & 18 carat;UK - 9 ct with 18 and 22 ct; USA - 14 ct with 10 & 18 carat Some countries insist that there is no negative tolerance allowed (e.g. UK, where 18 carat is 750 fineness minimum) but in others a negative tolerance, typically 3 parts per thousand, is allowed (e.g. in USA, a fineness of 747 would be accepted as 18 carat). This causes difficulty in the mutual recognition of national marks/hallmarks , a problem raised in the European Union by the Houtwhipper ruling recently. Thus a piece of jewellery assaying at 747 fineness would pass in the USA as 18 carat but fail in the U.K Assaying of JewelleryMeasuring the Gold Content (Fineness) of Jewellery. There are a number of methods for measuring the gold content - or â€˜finenessâ€™ - of carat gold jewellery. Measuring the gold content is known as assaying and many of the most commonly used methods are described in a recent World Gold Council technical publication â€˜The Assaying and Refining of Gold - a guide for the gold jewellery producerâ€™. This is available from your local World Gold Council office or direct from WGC, London (See: World Gold Council Technical Publications). A more detailed technical review of gold assaying techniques has been published in the WGC technical journal, Gold Technology, issue no. 22, July 1997. A more recent overview is to be found in Gold Technology, issue no. 32, Summer 2001. Which method of measurement is selected depends on the accuracy of measurement needed and the speed and ease of measurement. The cost of the equipment (instrument) will also influence the decision.Fire AssayThe most accurate method, with an accuracy of 2-3 parts per ten thousand (0.02%), is the Fire Assay (Cupellation) method. This involves taking a small scraping from the article, typically about 250 milligrammes, weighing it accurately, wrapping it in lead foil with some added silver, cupelling it in in a furnace at about 1100Â°C to remove all base metals and then placing the resulting gold-silver alloy button in nitric acid to dissolve out the silver (known as â€˜partingâ€™) and re-weighing the resulting pure gold. This is the standard reference technique used by the national Assay laboratories worldwide for Hallmarking and is covered in the International Standard, ISO 11426:1993. A good description of the process is given in an article in Gold Technology, No 3, January 1991. A simplification of this technique involves omitting the initial cupellation stage and just melting the sample with added silver and/or copper, rolling to a thin sheet and then dissolving out the silver and base metals with nitric acid. This is satisfactory only when there are no other impurities present, but will be less accurate.Inductively Coupled Plasma SpectrometryFire Assay is closely followed for accuracy by Inductively Coupled Plasma (ICP) Spectrometry, which involves taking a smaller sample of about 20 milligrammes, dissolving in acid and subjecting a sample to analysis in an ICP (Inductively Coupled Plasma) Spectrometer - an expensive instrument. This technique has an accuracy of 1 part per thousand but requires use of comparative standard reference alloy samples of known composition. This technique is accepted for Hallmarking purposes and has the advantage in that it also measures the other alloying constituents.X-ray fluorescence X-ray fluorescence (XRF) is a non-destructive technique that is suitable for normal assaying requirements such as in-house quality control in manufacturing or for â€˜certifyingâ€™ gold content in retail outlets. It has an accuracy of, typically, 2-5 parts per thousand under good conditions, i.e. where the surface of the jewellery being measured is relatively flat and sufficiently large. On curved surfaces, the gold X-rays generated and measured are scattered and accuracy is reduced significantly. It is a quick technique, an assay taking about 3 minutes, and the results can be automatically printed out by the computer. It also measures the content of the other alloying metals present. However, it only measures the gold content of a thin surface layer, so accuracy is severely compromised where the jewellery article has had a chemical surface treatment (to enhance colour) or has been electroplated with a layer of pure gold.The more accurate XRF instruments measure the intensity of the generated gold X-rays by wavelength dispersion analysis. The use of energy dispersive analysers results in cheaper instruments but reduced accuracy. Reference alloy standards, of known composition close to that of the test piece, are needed if accuracy is required in XRF testing.There are several instruments appearing on the market developed specifically for gold jewellery assaying, such as the X-tester, and these are more reasonably priced. A major retailer in India has equipped each of their stores with such instruments. The gold content of each piece of jewellery is measured as it is sold, printing off a Certificate, thereby guaranteeing caratage conformance and providing consumer confidence in a country where national Hallmarking regulations do not exist.Touchstone testingTouchstone testing is an ancient method for measuring gold content whereby a rubbing of the jewellery is made on a special touchstone alongside rubbings of known reference samples and treated with acids. The colour of the reacted area is compared to that of the reference sample. It is not sufficiently accurate (about 15 parts per thousand at best) and is only useful as a sorting test to differentiate between different caratages. It is less accurate at high caratages and with white golds. A more detailed description of the technique can also be found in Gold Technology, No 3, January 1991. Other MethodsThe Electronic Gold Tester (or the so-called Gold Pen) is a cheap, although portable technique based on the capacitance decay principle. Accuracy is poor, being correct to only 1-2 carats (4-8%) and is compromised if the surface is gold-plated, for example. It is useful only as a sorting test.The density of carat golds reduces as caratage is lowered and this gives rise to density measurement as a possible method of measuring gold content, using Archimedes principle. However, density is also influenced by the other alloying constituents and so the accuracy of the method is poor. Jewellery containing defects such as porosity would further reduce the accuracy of density measurement. It is not recommended.SummaryFor high accuracy, consistent with marking/Hallmarking regulations, only Fire Assay and ICP Spectrometry are sufficient. These techniques involve taking a physical sample (a scraping) from the jewellery item. For good accuracy, X-ray Fluorescence (XRF) analysis is suitable. Accuracy depends on the shape (geometry) of the item; it is best on flat surfaces. This technique is suitable for quality control in production and for certifying caratage conformance in a retail environment. It is a quick technique (3-4 mins) and does not require technical expertise to operate. Results are automatically displayed/printed out by the computer control. Suitable bench-top instruments developed specifically for jewellery use are available on the market. Reference standards are necessary.For sorting jewellery into different caratages, then the touchstone and electronic gold pens are suitable cheap, quick techniques.A summary of the techniques is given in the following table: Comparison of Assaying Techniques Technique Versatility Sample size Accuracy Limitations Equipment Cost Fire Assay Only gold ~ 250 mg 0.02% Modifications forNi and Pd Moderate $50,000 ICP Complete analysis ~20 mg 0.1% - High$150,000 XRF Complete analysis Non-destructive 0.1 - 0.5% Surface layer, flat samples Moderate $25,000+ Touchstone Only gold Almost non-destructive 1-2% Unsuitable for high carat and white golds Low$100 Electronic Pen Only gold Non- destructive 4-8% Not consistent Low$200 Density Only gold Non-destructive Poor Only for binary alloys Low$500 Marking of jewellery Most people refer to the â€˜hallmarkâ€™ on their jewellery, but this term is often loosely used. It is important to differentiate between a â€˜Markâ€™ and a â€˜Hallmarkâ€™. They have different levels of guarantee of the caratage! A Hallmark is applied only by an independent third party, typically an Assay Office, after the item has been assayed for gold content. It is also important to recognise that, in many countries, the caratages of jewellery allowed to be sold is fixed by law. For example, one can sell 9, 14, 18 and 22 carat gold jewellery in the U.K, but not 12, 19 or 21 carat, which are allowed in other countries. For a list of these for different countries, see link at bottom of this page.MarkingIn most countries, national law requires gold jewellery to be marked with its caratage or fineness. This is done by physically stamping the jewellery with a punch, although laser engraving is also finding application (see article in Gold Technology, no 24, 1998). However, the caratage mark is no guarantee of gold content in some countries where there is no independent system of â€˜Hallmarkingâ€™. In such countries, undercarating is not uncommon! The USA, for example, has laws that require jewellery, where marked, to be marked with both the caratage and the makerâ€™s mark (for traceability) by the manufacturer or importer but they are not policed or enforced strongly. Hence undercarating is not uncommon at the lower end of the market. Marking of jewellery is usually done by the manufacturer without any independent check. Thus your caratage conformity is not guaranteed; you rely on the jewellerâ€™s integrity. Unfortunately, undercarating of jewellery is not uncommon in some countries.HallmarkingIn other countries, there is a legal requirement for all jewellery to be tested (assayed) by an independent third party (typically, an accredited Assay Office). If found to be within tolerance, then the Assay Office marks the jewellery with a number of marks including the caratage or fineness, the makerâ€™s mark and the Assay Office mark. This is known as a Hallmark. Usually, the Assay Office guarantees its mark by law, so the consumer has legal redress against the Assay Office, if an item is subsequently found to be of substandard assay. This is a full guarantee of caratage conformance. A list of countries with independent Hallmarking systems is to be found in an article by R.W.E.Rushforth in Gold Technology, No. 27, November 1999 which discusses the various marking systems in use. What is marked?The marking of jewellery with its gold content varies from country to country. Some mark with the caratage, typically 18 or 18 ct (or 18K in USA and some other countries) and others mark with the fineness, e.g. 750 (e.g. in the U.K.). At 14 carat, the mark 14KP is found in the USA, the P indicating â€˜plumbâ€™ to differentiate between the US standard and the international standard for 14 carat. 0 Quote Link to comment Share on other sites More sharing options...
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