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Diamonds Natural Synthetic Imitations… Strategies for Certainty or Doubt regarding the nature of what we handle

The gemological landscape concerning the world of diamonds, due to the increasing prevalence of synthetic diamonds in the market, has caused confusion, issues, uncertainties, and doubts about the nature of colorless stones circulating in the sector. Many operators are still unaware or lack the necessary foundation to address the issues related to the “recognition” of increasingly complex materials in circulation.

The presentation will cover what aspects and observations can be made on colorless stones with simple instrumental equipment. Synthetic diamonds appear to be entirely identical to natural ones. The purpose is to provide useful indications to distinguish those that can be confidently identified as natural from those that may be suspicious. However, absolute certainty about their nature can only be achieved by relying on a laboratory equipped with specialized instrumentation and proven experience in identification.

Certainties and Uncertainties in Gemological Material Analyses

Since ancient times, gemstones have been cut, treated, and so on, to transform a mineral into what we now call a gem. However, even then, some individuals, either by “forgetfulness” or with intent, omitted and still omit part of the treatments used. This created the need to find methods of analysis to define the treatments and uniformly decide on nomenclature to correctly name each treatment. The scientific foundations of ancient methods, appropriately updated, are still used today for gemstone analysis. Modern analytical techniques require that an analysis be accurate, repeatable, and reproducible, but we all know that each gemstone is “unique.” Since each gemstone is “unique,” every piece of data must be analyzed, and subsequently, it must be related to other obtained data. The search for origin doesn’t always lead to a decision to specify a particular origin. Not all treatments can be identified immediately. Sometimes, new treatments or new origins can pose challenges for gemological laboratories. For this reason, it is always necessary to keep up with the times and the changes that come with them.

TITANIUM: A FORGOTTEN ALLOYING METAL FOR JEWELLERY ALLOYS?

In all precious metals for jewellery application, there is a desire for stronger, harder alloys, particularly at high finesses, that better meet the demanding conditions of modern lifestyles. There have been several attempts at developing improved strength alloys over the last 30 years, particularly for high carat golds. These have included use of titanium as an alloying metal to produce the gold – 1% titanium alloy, “990 gold”, and micro-alloying gold with calcium and the rare-earth metals. Despite good technical properties, such alloys have not met with significant commercial success and the reasons for this are not obvious. In many research studies for stronger alloys, the use of titanium as an alloying metal has been found to be a good choice for gold and platinum yet its use in commercial alloys of gold, platinum and silver appears to be unpopular. In this paper, we review the literature on the use of titanium in precious metals for jewellery application and seek to demonstrate why its use could be beneficial to the jewellery industry and what further work is needed to bring titanium-containing alloys into commercial use. Its recent use in developing improved strength 22 carat gold alloys for the Indian market provides an example of its potential in the industry.

Jewelry Solders and their Applications in the Manufacturing Process

What makes a good solder? Is it flow or how it wets, hardness or ductility, strength or melt gap that is the most important quality, or is it a combination of all of these? There are many examples of jewelers who claim solder “A” is excellent but solder “B” is not so good, while others claim exactly the opposite. Why is this? Can we quantify the physical and mechanical properties of solders to predict which will be good and which will not? Can we predict from this information which solders are best suited to specific applications, or is it like the above statement and purely a subjective assessment with a “if it works for you, use it” philosophy? This paper will discuss the principles behind metal joining, measure the properties of solders and solder joints in various applications and determine if guidelines can be identified to predict which solders will work best in specific applications.

Designing Future: Jewelry in the Digital Era 

The presentation explores innovation in the jewelry industry with a particular emphasis on digital transformation. The aim is to analyze the many contemporary contexts of jewelry, highlighting the effects of digitalization on aesthetics, materials, and the processes they influence. During the talk, we will explore the key elements of digital transformation in the jewelry industry, emphasizing its impact on artistic expression, material selection, and production techniques. We will also present and discuss case studies that illustrate scenarios of innovation, showing how digital technology integration has opened up new creative possibilities and design opportunities for jewelry. The session will underscore the necessity of ongoing adaptation in the jewelry sector. As technologies evolve rapidly, industry professionals must see these changes as catalysts for future research and creative innovation. Being able to embrace digital transformation and use it to one’s advantage is essential for staying relevant and competitive in a constantly changing market. The goal of this talk is to provide an overview of the current and future state of the jewelry sector in an increasingly digital age, offering reflections and inspiration for all those interested in the evolution of this industry.

The use of ED-XRF technology to measure gold assay after the introduction of ISO 23345

ED-XRF analysis techniques are becoming increasingly popular in the jewelry industry. The possibility of measuring a finished object of even complex shape, without destroying or ruining it, very quickly, is a unique attraction compared to other conventional techniques (e.g., ICP or fire assay). Despite their relative popularity, however, X-ray fluorescence-based techniques were generally relegated to a marginal role, limited to checking the rough composition, due to the perception that this type of measurement is inaccurate. Calibrating the analyzer with good references, choosing specific measurement parameters, and understanding the structure of the analyzed jewelry are fundamental in allowing much more precise and accurate measurements. In our tests, we work with and on the new ISO 23345:2021, which defines calibration, measurement, and interpretation of data for fineness analysis by ED-XRF.

Jewelry production by Binder Jetting Additive Manufacturing: our experience on Platinum 950 and Silver 925

The presentation continues the work previously presented at TJS in 2023 and is focused on the usage of Binder Jet technology for production of jewelry in Silver 925 and Platinum 950 alloy powders. Results from the use of 3D binder jetting systems with different precious metals based powders at our laboratories in Bressanvido, Italy will be showed; the experience so far proves Binder Jetting to be a realistic player in the world of jewelry production by additive manufacturing, although still undergoing a learning curve.

Steel in jewelry nichel-free surface treatments

Recently, the jewelry sector has also started to consistently employ steel, which represents a more economical but high-quality alternative to the precious alloys traditionally used in jewelry production. To achieve the same finishes already available on common jewelry alloys, surface treatments are necessary, which, however, can affect the steel’s structure, introducing corrosion phenomena and nickel release. This paper describes the current state of the art in galvanic and PVD finishing processes performed on steel, from surface activation to the types of finishes commonly used. In the second part, it also describes a case study on how galvanic cycles have been optimized to minimize and in some cases completely eliminate nickel release from treated steels.

Strategies for the development of new jewelry alloys

Alloy development plays a crucial role in the jewelry industry, aiming to achieve desired properties such as color, mechanical properties, and corrosion resistance. In this study, we explore the potential benefits of adopting strategies from other industries to enhance the alloy development process in jewelry manufacturing. This interdisciplinary approach integrates thermodynamic simulations and experimental high-throughput screening methods to accelerate the discovery and optimization of alloy compositions. Thermodynamic simulations are employed to predict phase stability, solidification behavior, heat treatment and alloy properties. By leveraging computational tools, researchers can effectively analyze the effects of different alloying elements on the final material properties. Additionally, experimental high-throughput screening methods are adapted to efficiently explore a vast composition space of potential alloy candidates. These screening techniques enable rapid fabrication and evaluation of a large number of alloy samples, allowing engineers to identify promising compositions for further analysis. The findings presented here can pave the way for innovative and sustainable practices for the development of new jewelry alloys manufacturing while offering new avenues for exploration and inspiration for the jewelry and watch industry.