The Armenian Jewelry Industry An Introduction

The jewelry industry in Armenia can be argued to have started during the 1980s while a satellite country of the Soviet Union. The country began its well-known diamond processing industry around this time, but saw a decline in 1991 due to the collapse of the Soviet Union.

Armenian jewelry has been known for its use of diamonds and other fine stones, and the unique designs on the jewelry that is often found in ancient burial grounds in the area. The obsidian gem is also a well-known gem from the area. The technique used to cut obsidian survived through the Soviet occupation. The jewelers will cut the obsidian so that it is paper-thin, giving it an oddly transparent quality. The obsidian found in Armenia is the purest in the world, making it the only variety suitable for the luxury jewelry market.

The designs found in Armenian jewelry go back hundreds of years. Flowers and circles are found in intricate patterns in ancient Armenian tombs and burial grounds. These patterns remain popular designs for use in bracelets and bangles today. Some pieces have multiple colors – earrings with strips of different colored gems are not uncommon for modern designs.

The cross is a favorite symbol often found in Armenian jewelry pieces. These crosses often have intricate designs – from pointed and looped corners to swirling leaves on the body of the cross. Other crosses are simple and elegant – with gems on the body of the cross and a cluster of three gems on each corner.

Gold and silver are common metals for ancient and modern pieces alike. Bronze is also common for more traditional pieces – such as headpieces for women with coins and rings. Bracelets with rings attached are also common for bronze jewelry in Armenia.

Long, dangling pieces are also very common on traditional pieces. A traditional pair of earrings can have ten or more pieces that dangle off the bottom of the earring’s base. Necklaces can have a large, central piece that is held by a single loop on the band. Some have clusters of dangling pieces in a pattern while other pieces have one cluster of multiple dangling pieces.

The Armenian Jewelers Association (the “AJA”) was founded in 1998 with the purpose of uniting jewelers from Armenia. The organization works to further trade, commerce, and jewelry manufacturing in Armenia.

The association aims to link those in the various positions in the jewelry business who are of Armenian descent in a spirit of cooperation, lobby for jewelry trade-friendly legislation, give a forum for Armenian jewelers to discuss their affairs, and to obtain good rates for various services that the jewelers need in order to market their products to the world.

The country of Armenia has a rich, fascinating, and sometimes tragic history, and the development of the jewelry industry in Armenia and by those of Armenian descent is an interesting study. Armenian jewelers are masters at diamond and stone cutting, and the patterns found in ancient burial tombs can still be found in Armenian jewelry today.

SYNTHETIC DIAMONDS |MAN MADE DIAMONDS

A synthetic diamond is chemically, physically and optically a real diamond, though grown in a machine rather than mined from the ground. They are commonly called man-made, lab-grown, lab-created or cultured diamonds (a term not favored by International gem standards organizations, as they feel it is deceptive or unfair, even though by definition [produced under artificial and controlled conditions], cultured is not incorrect.) and can be grown in yellow, blue or white/colorless through a couple methods.

History & Technology

Synthetic diamonds were first produced in the 1950’s by GE and ASEA using large “belt” style presses. These diamonds were small and heavily included with poor colors, so were far from being gem quality. Through the 70’s and 80’s, smaller “cubic” presses were developed and were able to grow gem-quality sizes, but still produced mainly brown and yellow industrial diamonds. In the late 80’s and early 90’s, a “BARS” press was developed in Russia which, to-date, is the most effective method of growing a large gem-quality diamond. BARS presses are able to grow rough diamonds up to six carats, though the polished yield depends mainly on growth cycle duration and inclusions throughout the rough diamond. All of these machines create a high pressure and high temperature (HPHT) environment where carbon atoms slowly build upon a tiny diamond seed in a molten metal solution.

Diamonds grown using HPHT technology can be most easily made in fancy yellow colors because it is very difficult to exclude nitrogen from the diamond’s crystal lattice. The nitrogen assists the growth of the diamond, speeding the process and making yellows the easiest and fastest color to grow. Fancy blue colors can be grown by trapping boron in the diamond lattice instead of nitrogen, similarly helping the speed of growth, but growing slower and therefore at greater cost than yellows. Colorless diamonds can be made by limiting nitrogen and boron from entering the diamond lattice. By removing these “helper” elements, the speed of growth is slowed, so the heat and pressure have to be sustained longer for a comparably sized colorless diamond. The longer the growth cycle, the more challenging it is to control the color and limit the inclusions, which is why colorless diamonds are the most difficult to produce.

In the 80’s, another process emerged for growing diamonds called chemical vapor deposition (CVD). This process uses carbon-laden gases, such as methane, in a low-pressure heated environment, using microwaves as an energy source. Plasma breaks apart the gasses and the carbon “rains” onto a diamond seed. This process primarily produces brownish and near-colorless diamonds, with their size limited by the thickness of the diamond wafer. Many CVD diamonds are then HPHT color treated to turn brownish and off-white colors into more desirable colorless and near-colorless diamonds.

ynthetic Diamond Identification

While all synthetic or man made diamonds are in fact real diamonds, there are various methods and testing equipment available to identify a diamond’s origin, as well as to detect non-diamond simulants. A common thermal diamond tester will accurately identify both mined and synthetic diamonds as real diamonds and stimulants, such as cubic zirconium, as being made of different substances as real diamond. Electrical conductivity tests are commonly used to detect simulants like Moissanite. They will correctly identify all white and yellow synthetic diamonds as non conducting real diamonds. All blue diamonds, mined and lab-grown alike, are electrically conductive, so will return false positives for any blue diamond when tested with very simple electrical conductivity tests.

More advanced tests can further identify synthetic diamonds. HPHT diamonds grow in a molten metal solution, so inclusions are metallic, while mined diamonds grow in molten rock and do not have metallic inclusions. Fourier transform infrared spectrometer (FTIR) or energy dispersive X-ray fluorescence (EDXRF) can both detect trace amounts of metal in HPHT-grown synthetic diamonds such as iron, nickel and cobalt introduced from the growth environment. Synthetic diamonds have both octahedral and cubic growth sectors, while mined diamonds only have octahedral sectors, which can be detected using a cathodoluminescence (CL) spectrometer. De Beers has also developed two machines, DiamondSure and DiamondView, which measure the light absorption at specific wavelengths and shortwave ultraviolet fluorescence, respectively, to identify synthetic diamonds.

Synthetic Diamond Availability

Synthetic diamonds are grown in three primary colors: yellow, blue and white/colorless. Yellow diamonds grow the fastest, so cost the least and are available in the largest sizes. They typically range up to two carats polished, though some exist up to four carats. Blue diamonds are available up to about 1.50ct. Gem-quality white diamonds are the most difficult color to grow, with limited availability up to one carat.

HPHT color treatment of yellow synthetic diamonds can produce yellowish-green colors while irradiation can produce pink, purple, red and vivid green colors. Most diamonds over 1/3 carat come out in vivid, deep and dark colors.

Depending on the color, irradiated diamonds may also require further high temperature heating (annealing). Irradiation is a safe procedure where the diamond is bombarded with electrons, which alter the diamond’s crystal lattice. Pink, purple and red colors are stable to around 800°C and greens are stable to around 350°C. This type of irradiation has no residual dangerous half life.

 

BLUE FLUORESCENCE IN DIAMONDS

Abstract:

Historically ‘blue white’ fluorescent top coloured (D to F on the GIA colour grading scale) diamonds were once priced around 10% more than non fluorescent diamonds. Today D to F coloured blue fluorescent diamonds are usually discounted on wholesale markets. There are two main technical reasons why fluorescent diamonds would be discounted. The diamond’s body colour may have been ‘over-graded’ or its transparency may have been impaired.

There are also several possible “commercial” reasons why high coloured (D-F) blue fluorescent diamonds are often discounted. For example, they may be more difficult to sell. This article will review the complex and often contradictory history.

Introduction:

In the USA the Federal Trade Commission banned the use of the term ‘blue white’ in 1938. In 1993, Martin Rapaport added a fluorescence price guide to the Rapaport Diamond Report apparently as a response to events in Korea. In 1997 the Gemological Institute of America (GIA) published a survey in Gems & Gemology indicating that blue fluorescence was a benefit to diamond face up colour appearance. Shortly after, without declaration, the GIA Gem Trade Laboratory changed its grading illumination environment used to grade D-Z coloured diamonds to include more ultra violet light. Cape or yellowish diamonds that exhibit blue fluorescence are believed by many to receive higher colour grades than when ultra violet light was absent. The author solicited opinions while researching for this article concerning possible links between fluorescence and transparency from several respected lab directors and trade experts. Worryingly, the views differed widely. The history, pricing and related issues are discussed and some conclusions are offered.

What causes fluorescence?

Diamond is a very pure mineral. The most common impurity is a tiny amount of nitrogen (0.0001% to 0.01%) dispersed throughout the crystalline structure. When white light traverses a yellowish diamond some blue light is absorbed by the deformities in the crystal associated with the nitrogen causing a slight yellow appearance. Higher energy ‘light’ like x-rays or short wave ultra-violet can also cause the diamond to fluoresce and emit in the same frequency range that was previously only absorbed. Natural ultra-violet from daylight or even from some light globes is enough to make a fluorescent yellowish diamond appear whiter. Nitrogen can also occur in various ‘states’ with different electronic properties within a diamond so that it is possible for one D coloured non-fluorescent diamond to have 10 times more nitrogen than another that is K colour and fluorescent.

History

Background

After the discovery of diamonds in South Africa in 1867 some mines were renowned for producing a percentage of high colour diamonds that exhibited a bluish appearance in daylight as a result of their fluorescence. It came to be that these diamonds, especially those that were otherwise colourless, were termed ‘blue white’ and sold at a premium price. However, human nature being what it is, some marketers of diamonds indulged in “bracket creep” and began to call diamonds of lower colours “blue white” in order to achieve a higher selling price and more profit. This led the United States of America Federal Trade Commission (FTC) to ban the use of the term ‘blue white’ on March 18, 1938 with the following resolution 23.14, (Trade Practice Rules for the Wholesale Jewellery Industry, Rule No. 6, p4:

23.14 Misuse of the term “blue white.”

It is unfair or deceptive to use the term “blue white” or any representation of similar meaning to describe any diamond that under normal, north daylight or its equivalent shows any color or any trace of any color other than blue or bluish.

Interestingly under this definition there are diamonds that could still be legally described as blue white, however it seems that the intention of the legislation has been observed, and, if anything, there has been an over-reaction. The FTC also made an attempt to define the type of lighting that might cause a diamond to fluoresce and appear ‘blue or bluish’. The detail however did not include terms such as ‘shaded’ or ‘indirect sunlight’ or make any reference to the time of day or atmospheric conditions. The quality of published industry and gemological opinion about the type of natural light that diamond colour ought to be judged or graded in, is poor and often contradictory, as can be noted in the following quotes.

Eric Bruton wrote in 1978 in ‘Diamonds’:

“A very important consideration is that any fluorescence in the stone must be suppressed. A visible blue fluorescence can be caused in a yellowish diamond when ultra-violet light, which is invisible, falls on it. If the diamond is examined in sunlight, even reflected light, which contains ultra-violet light, the blue fluorescence will tend to cancel the yellowish body colour because the colours are nearly complementary, and the stone will appear to be whiter than it is. These stones are often mistakenly called ‘blue-white’. It is therefore important to grade stones in white light that is relatively free of ultra-violet and the orthodox method is to use daylight from a north-facing window in the northern hemisphere and from a south-facing one in the southern, i.e. with one’s back to the sun.”

“…but it must be remembered diamonds are rarely seen in such ideal conditions in wear because there is some ultra-violet in most daylight.”

“False White” Stone: If a stone has blue fluorescence and a tinted yellow body colour, the colours being complementary may cancel each other so that in some conditions the stone appears white. The experienced grader will recognize such stones because their colour grade appears to vary in different light intensities. A white light free of ultra-violet will disclose the true body colour and an ultra-violet lamp the fluorescence.”

Mr. Bruton is the only author who attempts to describe an orthodox and accepted colour grading environment of shaded daylight which has often been referred to as the environment that artificial light should mimic. However, Bruton then seems to contradict his own comments: “even reflected light, which contains ultraviolet light”….. “A white light free of ultra-violet will disclose the true body colour….” “but it must be remembered diamonds are rarely seen in such ideal conditions in wear because there is some ultra-violet in most daylight…..”

In 1986 Eddy Vleeschdrager wrote in ‘Hardness 10: Diamond’:

“A polished diamond is less valuable if its fluorescence is too high, for it will give the impression of having a better colour than it actually has in normal light conditions. The colour of a diamond has to be determined using a normalised artificial light source which corresponds to daylight. Because this light source simulates day light, it contains an amount of ultra-violet light. It is evident that the ultra-violet light will contribute to fluorescence.”

It is interesting to note the contradictions in Mr. Vleeschdrager’s quotes. A diamond should be less valuable if its colour is better in normal lighting? A diamond’s colour should be determined in ‘normalised’ artificial daylight which should contain an undefined amount of ultraviolet light. Did Mr. Vleeschdrager really intend to say that blue fluorescent diamonds will be overgraded in a normalised artificial light source, which by his own definition, should contain some unspecified content of ultra-violet light?

In 1980 Verena Pagel-Theisen in the 7th edition of ‘Diamond Grading ABC’ wrote:
“the body colour observed in normal light determines the colour grade of fluorescent diamonds” although there is no description in this book as to what constitutes ‘normal light’.

In the 9th edition of the same book, in 2001:

“…the body colour observed in standardized light determines the fluorescent diamond’s colour grade.”‘Normal light’ has become ‘standardized light’, but there is still no attempt to define a standard.

There is however an additional notation that “In the upper colour grades up to ‘white’, fluorescence means a reduced price because clear fluorescence can affect the transparency and clarity of the stone.” There is a recurrent theme in “Diamond Grading ABC” that fluorescence may affect the transparency of higher colour and clarity stones more than in the case of lower grades. If this is so then it has neither been discussed nor validated in the literature. In this writer’s diamond grading experience it does not appear to be the case. One can also only wonder why the term “clear fluorescence” was used in the same sentence as “transparency”

It becomes apparent from a review of the literature that there is no clear idea of what type of natural or artificial light should be used for diamond colour grading. It should also be noted that there have been no attempts by gemmologists or diamond grading laboratories to clearly define, describe or rate the levels of transparency that may be reduced in diamonds that fluoresce, or for that matter even in those that are inert. Transparency will be a recurring topic in this article.

KoreaGate’ In an interesting case study, prior to 1993, Korean retailers and consumers exhibited a preference and paid a premium for blue fluorescent diamonds. However a Korean current affairs TV programin 1993 accused local Korean grading laboratories of over-grading the colour of fluorescent diamonds, suggesting for instance that “your G is really H”. Korean traders replaced many of the fluorescent diamonds they had sold earlier, becoming net sellers of fluorescent goods and buyers of non-fluorescent diamonds. This simultaneous dumping and demand of the different grades of goods seemingly contributed to an adjustment in the Rapaport Diamond Report price guide. A month or two later a chart appeared (Table 1) with price guides for blue fluorescent diamonds of different colours and clarities. This guide is still in place today, having had only some minor adjustments from time to time which presumably only reflect fluctuations in supply and demand.

In an article written by Martin Rapaport 1998 in the Rapaport magazine, entitled ‘Blue White’ Martin wrote:“Once upon a time, before the diamond industry standardized to GIA color grading terminology, the term Blue White (Blauweiss) was used to described the finest color white diamonds. The original Blue White diamonds came from South Africa’s Jagersfontein mine. The best Jager stones were highly transparent (clear and colourless) with a bluish tint due to fluorescence. Ironically, during the early part of the 20th century, fluorescence was seen as something that had a very positive impact on top colors”. And: “While education can play an important role, changing buyers’ perception about the negative impact fluorescence has on higher color diamonds will have to be backed up by solid results. In other words the labs are going to have to be very serious about not over-grading the color of fluorescent stones, even though these stones tend to appear whiter than they really are”.

AN OVERVIEW OF COMMON ALLOYS USED IN JEWELRY

Fine jewelry settings are created from precious metals. This article addresses some important information about gold, white gold, rhodium plating and nickel allergies, as well as covering fine distinctions between common platinum alloys. Many alloys exist and new ones are constantly being developed. Here is an overview of some of the most common encountered in the crafting of jewelry

1. GOLD

Gold is popular because it can be worked into almost any shape. Yellow gold jewelry of 18K and above does not tarnish and rarely causes problems for people with skin irritations. White Gold is popular for its appearance and price point compared to platinum alloys.

Technically there is no such thing as ‘White Gold.’ Gold can be lightened by combining it with light metals but we plate all WG pieces with Rhodium; a member of the platinum family and the whitest precious metal after silver. This rhodium plating creates a hard skin with good resistance. Over time plating may wear through. Re-plating is a fairly simple process, depending on the condition of the piece. In most cases this will be done approximately as often as a platinum ring requires re-polishing, although a fine plating job may last longer than a polish on platinum due to the superior hardness of rhodium.

COMMON GOLD ALLOYS

24K gold (100% pure gold) does not work well for jewelry because it is too soft. A more durable option is 18K gold, which is 75% pure gold. It has the richness of 24K gold where some of the less pure alloys may not.

Identification

18K gold is the most recognized global standard and will be marked ’18K’ in the USA and ‘750’ in Europe.

1. 18K Yellow Gold

  • 75% Gold, alloyed with Copper, Silver, Zinc and/or Cobalt
  • Does not require plating
  • + Very workable
  • + Rarely causes skin irritation
  • – Will wear down, but over a long period of time with heavy wear

2. 18K White Gold (nickel white gold)

  • 75% Gold, alloyed with Copper, Nickel, Zinc and/or Palladium
  • Requires rhodium plating and re-plating over time, depending on wear
  • + Less workable, less ductile
  • – Causes skin irritation for people with nickel allergies
  • – Will wear down over a long period of time

3. 18K Palladium White Gold

  • 75% Gold, 25% Palladium
  • Requires rhodium plating and re-plating over time, depending on wear
  • + Very workable
  • + Rarely, if ever, causes skin irritation
  • – Will wear down over a long period of time
  • – More expensive than 18K nickel WG

Comparison Photos

  1. 18K yellow gold
  2. 18K white gold, rhodium plated
  3. 18K palladium white gold, not plated

2. PLATINUM

Platinum is a versatile, eternal metal. It does not fade or tarnish and is ideal for those with sensitive skin because it is hypoallergenic. It is the safest, most suitable and versatile metal for durably setting any kind of gemstone.

Platinum’s density gives it a unique quality. When platinum scratches none of the volume is lost, the metal is merely displaced as ridges are raised on the edge of the scratch. As platinum is worn it develops a patina-like appearance. It can be polished again and again because this is just moving the metal around, not wearing it down. Other precious metals lose material over time. Gold prongs wear down and rings can get thinner with wear. Platinum prongs bend but rarely break and do not wear down.

COMMON PLATINUM ALLOYS

There are 4 platinum alloys commonly used in the USA.

  1. Pt900/Ir = 900 parts platinum, 100 parts Iridium
  2. Pt950/Ir = 950 parts platinum, 50 parts Iridium
  3. Pt950/Ru = 950 parts platinum, 50 parts Ruthenium
  4. Pt950/Co = 950 parts platinum, 50 parts Cobalt

A Common Misunderstanding

When people hear Pt950 described as 95% platinum they assume that means 95% by volume. It doesn’t. The percentage is by weight. Platinum is the heaviest of these metals. Therefore, it will require more than 5% by volume of a lighter metal to match platinum by 5% in weight. This misunderstanding is merely academic information that may be of interest to some people.

Atomic Weights

  • Platinum: 195.078
  • Iridium: 192.217
  • Ruthenium: 101.070
  • Cobalt: 058.933

 

Identification

  • 95% platinum is the world standard, marked 950 plat in country of origin
  • 90% platinum is a popular and traditional USA standard, marked 900Pt
  • 50%-90% platinum may be marked Plat in other countries, but only 950 platinum can be marked Plat in the USA

Alloy Comparisons

Pt900/Ir (900 parts platinum, 100 parts Iridium) is a good hard alloy. A great compromise between relative hardness for easier polish it has excellent white color and is still quite malleable. It is excellent for both casting and handmade work. Less pressure is required to set gemstones than with harder alloys. It is resistant to scratching & bending and over time is very resistant to signs of wear.

Pt950/Ir (950 parts platinum, 50 parts Iridium) is a good medium-hard alloy which is malleable and well-suited for bench work. Good for casting and excellent for handmade pieces, it is the best choice for soft or fragile gem setting. The greater softness requires a longer polishing process. It is less scratch and bend resistant than harder alloys but holds a stone better if an impact occurs; like a shock absorber. Over time it is very resistant to signs of wear.

Pt950/Ru (950 parts platinum, 50 parts Ruthenium) is very hard. It has the highest melting temperature of all platinum alloys and is difficult to cast. Darker gray in color than platinum-iridium, it is less malleable, hard to solder and weld and hard to burnish. Bench workers find it tough on burs, files and drills. Some setters recommend it for diamonds only, since more pressure must be imposed on gemstones during the setting process. It is extremely scratch & bend-resistant and extremely resistant to signs of wear over time.

Pt950/Co (950 parts platinum, 50 parts Cobalt) is moderately hard. With the lowest flow point of these alloys it is good for even, dense castings of finely detailed pieces or filigree but not for work by hand. This alloy tarnishes when heated so it needs flux and pickling after soldering just like gold, unlike other platinum alloys. Since Cobalt is a ferrous metal, not from the platinum group, its scraps must be kept separate from other platinum scraps. It takes a fast polish but finishes darker gray than iridium. It requires moderate pressure on gemstones during the setting process. Bench workers find it more “gold-like” and easy on the tools. It wears quite well over time.

Platinum/Iridium is the whitest and the softest alloy, excellent for production and setting. It solders and welds better than other platinum alloys. In the USA Pt900/Ir is a popular and traditional standard. The global platinum standard is 95% by weight, so manufacturers with a global clientele use Pt950/Ir.

The Most Important Element

The way the piece was formed, the heat treatments, welding and soldering applied and the skill of the craftsmen involved are all as critical to the final product as the alloy itself. Seasoned craftsmen and smiths may develop a favorite based on personal experience but no platinum alloy is “better” or “worse” than the others. In fact, the most important element is the way the piece is cared for. How the wearer cares for the ring will be more significant to how it holds up over time than any other factor. The skill level of the craftsman is equally important. Whatever alloy is used comes in far behind the first two considerations.

Platinum is used in industry and medicine as well as for fine jewelry applications. In all cases we feel platinum is a wonderful choice for a lifetime of wear.

Comparison Photos

  1. Platinum-iridium
  2. Platinum-ruthenium
  3. Platinum-cobalt

 

3. HARDNESS AND DURABILITY

In discussions about precious metals people often confuse hardness with strength, but they are not the same.

Hardness = HV

Often referred to as “scratch resistance,” hardness is measured using the Vickers Hardness scale. This tests the hardness of a metal by pushing a pointed object into the surface with a specified load and gauging penetration.

Durability = PSI

Tensile strength, or durability is measured in pounds per square inch.

Comparisons

  • 18K Gold = 125 HV…29,000 PSI
  • Pt900/Ir = 110HV…55,000 PSI
  • Pt950/Ir = 80HV…40,000 PSI
  • Pt950/Ru = 130HV…66,000 PSI
  • Pt950/Co = 135HV…64,000 PSI

Gold is harder than some platinum alloys and will resist scratches better. Platinum is almost twice as durable as gold, is more ductile has much greater longevity. For the body of the piece the differences are not critical. For the prongs they have implications: For instance, white gold prongs will break. Yellow gold prongs will bend more, as will platinum, but platinum prongs are more durable over time.

4. OTHER ALLOYS

The alloys above are most common in our experience, but many other alloys exist.

Colored gold alloys range from 8 to 22K in gold content and can be produced in color shades such as rose and red (greater copper content), green (more silver) and even purple (gold-aluminum).

White gold alloys using chromium and iron instead of nickel have been developed to address the problem of nickel allergies.

Stuller’s new X-1 14K white gold alloy has good whiteness and passes the EU Nickel Release tests. It is yet untested for longevity and durability.

950 Palladium is similar to platinum alloys; 95% palladium alloyed with 5% ruthenium by weight. Like platinum alloys it only requires occasional repolish. However, it is not as white as more common Platinum/Iridium alloys and is priced similarly and not many people work in it.

Plat/S+ is another 950 platinum alloy offered by Hoover & Strong (the remaining ingredients are proprietary). Harder than other traditional platinum alloys, it was developed by the late Steven Kretchmer, who introduced tension-set rings in the USA, under the name SK Platinum.

950 PlatOro is 95% platinum and 5% gold by weight. Also from Hoover & Strong, it has high flow characteristics which keep porosity to a minimum. It is ductile, with similar hardness to Pt950/Ru.

New alloys are constantly being developed. As with precious stones, the variety of offerings and options available to the consumer in precious metals and alloys reflects the wide variety of taste among enthusiasts.