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Expert Advice >
Choosing the right metal
There are many articles on precious metals on the web and some of them are quiet professional with a lot of details and data. I will try not to give you just another one. Here I will offer you a simple version and avoiding extensive technicality add my professional opinion on the best use of these metals in order to utilize their unique properties. In this article we will focus on the most popular precious metals used for jewelry: gold, platinum and the fast growing in popularity palladium.
Pure gold and platinum are soft metals which are extremely dense. pure gold is about two and half times heavier than iron and pure platinum is just under three times. While really bright in color pure metals are not suitable for fine jewelry because of their softness. Soft metals are easy to damage, difficult to polish, and unsuitable for detailed work. This is why they are mixed (alloyed) with other metals, in order to give them the desired properties. This is also where all this “carats” and confusing numbers come into play. In fact it is pretty simple. All pure metals in nature are white or gray in color except two, gold – bright yellow and copper- reddish pink. Now we go back to precious metals. All different colors of precious metals are achieved by mixing these colored metals with white ones. Carat is a confusing name for purity or fineness of precious metals. It is confusing because the same word is used as a weight measurement for precious stones. That carat is equal to 0.2gr. and have nothing to do with metal fineness. To differentiate the one carat from the other, in some standards, weight carat is marked with (ct) and purity karat with (kt). We can accept this rule to avoid confusion in further articles, therefore when we address metal purity we will use “karat”. Karat is used mainly to define purity of gold alloys. Different countries have different standards for gold purity and the most used globally alloys are: 9kt or 375, 10kt or 416, 14kt or 585, 18kt or 750, 21kt or 875 and 22 or 916. The alternative number which alone can be used as hallmark indicates the number of fine gold parts in the alloy out of 1000. The easy way to translate this into manageable information is to perceive it as the percentage of fine gold used x10. For example 750 means 75% pure gold content or 18kt. Platinum is used in almost pure form and 95% hallmarked 950 is a standard alloy. All alloys with pure platinum content of 95.0% or higher can be also marked with the full word “platinum” or “”plat.” Other used alloys are 900 (90%), 800 (80%) and 585(58.5) also called karat platinum. The amazing qualities of this amazing metal are better described in another article where I am comparing it with the white gold alternative. Palladium is usually used in 95 % purity alloyed with ruthenium. It is very white and it is used as whitening metal for white gold alloys. Soft as pure metal, when alloyed palladium is attaining toughness better than most white gold alloys, still retaining its malleability. These mechanical properties are making it a perfect for stone setting media. Palladium 950 alloys are as white as the platinum, blending well with white diamonds and eliminating the need of rhodium plating. Palladium is a light metal with weight close to the one of sterling silver and much lighter than platinum and high carat gold alloys, thus making it the metal of choice for items like large earrings. At the time of writing, the price of 950 palladium alloys is about a third of the price of the 18k white gold offering great possibilities for large solid pieces at significantly reduced price. One disadvantage though is that quality casting of palladium requires materials and equipment, currently not viable for small workshops
The hallmarks you will usually find on your precious metal jewelry are:
1). Karat or fineness stamp (e.g. 18kt/ct or 750)
2) Manufacturer’s stamp
The karat stamp does not have much value without the manufacturers stamp because the declaration of purity is not signed. Beware; in most countries you can buy a karat stamp for few dollars. Variety in gold colors and mechanical properties is achieved by alloying fine gold with one or more other metals. White gold for example is a gold alloy with whitening metals, usually palladium, nickel or silver or combination of them. Since the fine gold is always yellow, it is the alloy (base) metals that give the karat gold its color and properties. For example to be able to stamp an item as 18kt it must content at least 75% of fine gold. The remaining 25 percent of alloy metals will determine its color and physical properties. If 8.4% of copper and 16.6% silver is used in the alloy, we will end up with the traditional rich 18kt yellow gold color. If we mix the same amount of fine gold with 15 % of palladium and 10% of silver we will have good quality white gold. The constant content in 18karat gold alloy is always 75% pure gold. Higher than 18kt white gold alloys are not possible because the alloying metals are not in sufficient quantity to absorb the yellowness of the pure gold. 21 or 22 kt. gold is always yellow, very yellow. The same principle applies for platinum and palladium, although these metals are used in much purer form (95% is a standard) and there is not detectable changes in color. The only changes there are in physical properties. Now, with our newly acquired knowledge of precious metals we will probably arrive at the questions: What are the best alloys? What metal jewelry should I buy? Different metals are good for different purposes. As a general rule (and if you can afford it) buy alloys with higher precious metal content. That applies mainly for gold, since platinum and palladium are used in almost pure form. 18kt gold or higher have distinctive gold color and real precious metal properties. My opinion is that alloys with less than 50% gold content (under 14kt) should not be called gold, but gold brass or something else defining the inferior gold content. If you are looking for big bold and heavy pieces the best is to go for silver with gold accents or the very new precium (25%palladium and silver alloy developed by Handy & Hartman)which may be already on the market at the time you read this article. For your fine jewelry pieces choose 18kt gold and platinum. 18kt White gold can be used for heavier thicker pieces while platinum is the best for delicate settings with a lot of detail. It does not make sense to set R50 000 diamond in white gold just to save R2000 difference on platinum setting. Besides the aesthetic superiority, the security of platinum setting is immensely greater .When we come to earrings, especially large ones, choosing lighter alloys is essential. Palladium is the first choice followed by 14 kt white. For yellow, stick to 18kt. You can never get the right color in lower karats. Then, your goldsmith’s ability to work light will come handy. Try to find the right craftsman. It is really making all the difference. The weight of the stud settings is rather small even in the case of large diamonds, thus making the platinum the obvious choice for white metal. The difference in price will be insignificant but the difference in strength and safety and quality - vast. Another advantage of the platinum studs – they could be made very delicate and retain their strength.
Appearance Based Choice of Diamond (ABCD)
When it comes to diamond choice, whether for engagement ring or as gift for any occasion, one is often engulfed by an ocean of controversial information which seems to grow in complicity as one learn more. First comes the 4Cs system and its implications on the price and as soon as one figures out what is all about, there comes the certificate origin, proportions, fluorescence and many more, each one claiming different degree of importance. At the average cost of two to three monthly salaries it is not difficult to see why the potential diamond buyer is determined to make the right decision. My honest opinion however, is that the marketing efforts of the diamond merchants are often misleading, pushing the buyer to an unfavourable choice. Why would the merchant do this?
The logical reason is the bigger profit related to more expensive merchandise on all trade levels, thus the interest to promote certain qualities in favour of others. I have about 20 years experience in designing and selling diamond jewellery, and my opinion is based on that experience rather than on statistics or scientific research. I am trying to simplify the riddle of choosing the right diamond and separate the information that really matters from the one that doesn’t.
From this point I want to separate the diamonds bought for investment purpose, and possible intention to sell over time for profit. Although you will be often assured that the diamond you are buying is of investment quality this is most of the time half truth. Diamonds which can generate considerable appreciation are classified as extremely rare and are also extremely expensive. They should be of top colour and clarity, and most important, over 2 preferably 3 carat in size. I have another article dedicated to investment diamonds for those who want to know more. For the purpose of this topic, it will be enough to say that if your diamond cost less than $50 000 it is unlikely to generate reasonable interest. With this in mind the only other purpose of a gem quality diamond is its beauty. Since the beauty of the diamond is in its appearance, choice focused on qualities that visibly contribute to the appearance should constitute favourable choice. The key word here is visible. All the segments forming the diamond quality are making difference in its appearance, but while some are really evident others are completely undetectable for unaided eye. Addressing those segments in order of importance will certainly result in locating the best value for money choice. These segments in order of importance appearance wise are Cut, Carat, Colour and Clarity.
Cut is hardly mentioned when diamonds are quoted but it is of major importance for the appearance of the diamond. The amount of light reflected back from the facets of the gem creates the look diamonds are famous for. Ideal cut is not a necessity but a bonus if it does not add to the price. Excellent and very good graded diamonds are safe choice, but anything under that must be approached with caution.
Size does matter when it comes to diamond appearance and while many women will state that small diamond of good quality is OK they seldom mean it. The lack of sufficient information and inability to compare different options are most likely the source of such opinion. It is very difficult (financially) to go for diamond which is too big. Diamonds are very expensive even in small sizes and an effort to save for future expenses with higher priority is fully justified. My advice is not to spend more but to
consider the biggest size within certain budget. The appearance of a large diamond cannot be emulated by a cluster of small ones and a difference of even 0.2mm in diameter is surprisingly noticeable.
Going down on colour is possible and although the exceptionally white D, E and F grades are stunning G, H and even I colour looks perfectly white if there is no whiter stone next to it to compare. Choosing colour H instead of E for example will award you with considerably larger stone with far greater appearance impact.
High clarity is an all capital NO in Appearance Based Diamond Choice. Clarity is the place one could safely save big and push far the size or/and colour of one’s diamond. Inclusions in SI 1 graded stones are usually invisible for the naked eye and definitely do not affect the overall appearance of the diamond. The clarity grading system is based on size and number of inclusions and not on their colour and position within the stone. Diamond graded SI2 with small scattered white inclusions close to the girdle will appear much cleaner than one graded VS2 because of a single small black dot in the centre of the table, reflected many times form the facets. The price however will be based not on the appearance but on the grading and the difference will be huge.
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