Diamonds, Emeralds, Guide to Geneva, Jeweller, Jewellery, Jewelry, Mining, Specimens

By Appointment with: Dr Thomas Hainschwang, international award winning diamond specialist and multi-disciplinary gemmologist



Dr Thomas Hainschwang is an international award winning diamond specialist and multi-disciplinary gemologist, with a doctorate in ‘Type 1b diamonds: Correlations between the physical and gemmological properties of diamonds containing isolated nitrogen’.

It was a breezy, blue skied and sunny weekday morning. After a minor technical glitch, greetings and housekeeping were complete, we were underway.

Are you in the lab today?

Yes I am

Okay, let us get straight to it. There are set questions but if you want to elaborate, you’re more than welcome to. Who do you work and interact with in your role?

Watch manufacturers, pearl traders, gem traders, gold traders, jewellery manufacturers, auction houses. We get to work with an entire range in the supply chain of jewellery. We have also worked directly with Muzo Mine.

So you get to see an array of people, and products from all over the globe?

Yes gemstones that are cut, uncut, as well as set in jewellery.

What made you choose diamonds; why did you specifically select and set your focus on diamonds in particular; instead of, for example coloured stones?

It is especially the spectroscopy aspect that is fascinating, with coloured diamonds. I like coloured diamonds, from the wide variety of colours – from fancy colour diamonds. From a spectroscopy perspective, diamonds are more fascinating in comparison. Even after twenty years of working on this topic, the results are extraordinary. I still discover findings I have not known about before, that is something that is unlikely to happen by analysing quartz, emerald, ruby or sapphire – which have relatively and comparatively little to be found in terms of spectroscopic methods.

During our research we found that you invented an instrument within the field of spectroscopy, can you tell us a little more about that?

More than one, at our lab there are several prototypes – I have built spectroscopy systems, and imaging systems for gem testing specifically.

Wow, incredible. So your inspiration has been drawn from more than twenty years in the field. Where did the inspiration to create these instruments come from?

I saw quite quickly that many of the instruments available on the market aren’t really made for gem testing. Many come from chemical industries and physics labs, and mostly made for liquids or powders, or pre-formed slabs.

Based on innovation, a natural progression and an organic demand for these products within the industry, it made sense to build this?

Yes, specifically for gem testing, this is what I based my decision on. I also saw that if there were any issues in terms of modifications, maintenance and repair with commercial machines, we needed external technicians to come to the lab for repair work – which became very costly, and is time consuming. It made more sense to create, build and market from our own [gem specific] labs.

Are you doing this on a per instrument basis?

No, we are innovating and modifying all of the time, as needed. This can be one instrument, or several at the same time.

It is truly fascinating and no doubt, contributes to you staying in this role. Speaking of which, what else would you say keeps you motivated to stay in this role? With more than two decades of experience, what motivates you to go back every day?

That’s easy. There is always plenty to be discovered. It is not a job like any other. I have the opportunity to see things like never before, as well as have new experiences on a regular basis. Every now and again, I get to see new discoveries that are yet to be seen before. From the gem testing perspective, it goes beyond diamond [and gem] grading, I get to do research, testing fascinating gemstones – again, some of which have not been seen before, new gem species, new sources, there’s always something new in this business. Additionally, in terms of equipment, when I have a new idea or new source, I then have the chance to build something around it, trial, and keep working at it, until it is at optimum functioning. It is fascinating!

Of course, we cannot question that at all! Describe the current gem lab research environment in Switzerland? Is it different to 5-10 years ago? How does it compare to when you first started in the field of gemstone research?

In Switzerland we have quite a few labs, and they stay rather constant with little change. We have Gubelin Gem Lab, SSEF (Swiss Gemmological Institute), GRS (Gem Research Swiss Lab), and us GGTL <> (Gem Tech Lab/Gem Lab merger). That is quite a lot for Switzerland, as there are major labs present as mentioned, Gubelin and SSEF, that is several considering the size of the country, compared to Germany (where there is one lab), and Austria (a much smaller operation).

So the neighbouring countries must rely on Switzerland quite a lot?

Yes, many European countries rely more on Swiss labs, in comparison to their own. Relative to the size of Switzerland, we have many labs here. Which of course is closely related to the fact we have a large watch manufacturing hub (and history of watches), a substantial jewellery industry, the gemstone industry is comparatively big also. Looking at the flow of gemstones [from mine to market], several go through Geneva – that is reflective in the number of labs we have.

But do you think there is anything in particular? Much like San Francisco is home to start-ups, the digital and tech worlds, there’s something about Switzerland that one can’t quite put their finger on, but there is certainly something about the country that makes people [from the watch, jewellery, and gemstone industry] set up there. Or for example you mentioned a colleague that left, and then came back – there must be something magical about it.

It started with Gubelin [in Switzerland] – they were pioneers in gem research. It started here, and that is how it stayed here. From the onset, 1970s onwards, it was evident that vital research was taking place that may be a contributing factor. In addition, Switzerland has always been the home of several luxury goods. Take Austria as an example, they have lots of dealers yet they wouldn’t be able to open as many labs.

Why not, is this directly connected to demand?

Yes, their focus is more on jewellery – and labs as we have here [Switzerland] are not required to test jewellery, their market just differs to ours

Austria is more focussed on a different section of the supply chain

Yes, absolutely

It was interesting to note Sarine’s experience of AI (with the use of advanced learning machines such as automated and objective grading of a polished diamond’s clarity and colour), a truly modern day advancement in our industry, and we have discussed the previous five years, so which direction do you see this area of research going, in the next 5-10 years?

The industry is changing; it is not as ‘easy’ as it used to be. Some markets (and territories – China, Russia, and certain areas in Asia) have become more conservative in recent years. We used to regularly see large groups of tourists coming simply to shop, in the luxury sector; this is now decreasing. The industry as such is changing; this is also seen with watches. Even with Baselworld there are drastic changes, because there has been an increase in amounts charged to exhibitors, and the response has been clear – exhibitors do not want to be charged exorbitant fees.

It’d be a shame to lose Baselworld, as it is such an integral part of our industry’s calendar.

We are not losing it per se, it is just getting shorter – which has resulted, as many have state, in dealers who are no longer returning because the booth cost in comparison to say, Hong Kong is substantial.

To the point it is no longer worth their while?

Yes, exactly. Have heard lots of complaints, which have been going on for years, yet the organisers are ignoring it entirely.

Which is truly a shame, as once they have gone, that is it, and they’ve gone. We rely a lot on trust in our industry, so this is unfortunate. Are there any other trade shows you attend? You mentioned Baselworld. What about Tucson for example?

More so as a visitor, than exhibitor. We have exhibited in the past with the Rapaport, and Freiburg in Germany. Yes, in attendance at Tucson every year.

To catch up with colleagues, meet old friends?

Yes, it is the perfect opportunity to do that

Of course, it is intriguing. One gets to meet people from all walks of the ‘gem life’

Tucson really is the best place for this!

Usually at this stage of the interview, we ask the interviewee’s favourite creator in their field, for example an artist’s favourite artist/art movement, jeweller’s favourite jewellery house. As a scientist and director of a lab, what would you say are your favourite findings from a particular lab? What is the impact of the findings on the industry?

There are a couple of things. My PhD was certainly important, related directly to coloured diamonds. I have done quite a lot on spectroscopy, coloured diamonds (and testing), and pearl testing. We were first to analyse a scam that happened in 2010, where there was an attempt to pass off beads as natural pearls. Our findings were significant, because to see and be able to describe what was going on had an impact. There was another incident involving a parcel of topaz, that had each gemstone cut into a rough diamond shape, and an attempt was made to sell them as natural diamonds. This was of global significance, as it was happening all over the world. Additionally the leaps we have made in diamond testing, and gem testing equipment.

What inspired you firstly to pursue your PhD in physics, and secondly to research 1b diamonds for your thesis?

I started somewhat late. It was Emmanuel Fitch who was a friend of mine, and then my professor for my PhD. I studied his gemmology diploma; we became friends and researched together. He then suggested I pursue my doctorate – which I thought was outrageous at the time, as I was working full time – yet he convinced me to try, once I started I went for it!

You haven’t looked back? “The rest is history”, as they say?

It was rather harsh and a trying time, yet here I am, I did it!

Would you recommend your path to any budding gemmologists [/geologists/mineralogists/those starting out in this industry], if they are really interested in the research aspect, to do as you did?

As I did with the PhD in physics, or labs in general?


In general going independent, and doing what I did more than twenty years ago was pretty ‘out there’, because starting a gem lab from scratch as I did without having any background or industry support – 99% of the time, this model wouldn’t work. It is only thanks to being persistent, certain positive coincidences, plenty of hard work, good strategy, you name it… thanks to all of that, somehow it worked! So I wouldn’t necessarily recommend to anybody who starts out as a gemmologist in a lab, to then go on to start a lab from the very beginning. Yet for somebody that can find a work environment to work in a laboratory, to pursue a PhD I can absolutely recommend. It provides an entirely new perspective, and they would learn to work independently on a research topic – which is of utmost interest, more so if they have never done that before.

Would you say that your thesis came about as a result of decades of work in this field? You mentioned starting it a little late, yet in actual fact if it wasn’t for all those years of experience, you may not have selected your thesis in the same way, or that topic at all.

Exactly, absolutely. My thesis and quality of my thesis is as a result of many years of experience that I already had, and that is how my thesis came along, and turned out the way it did. Had I started and completed it sooner, it wouldn’t be of the same quality nor significant a body of work, as it is now.

This is true. So on more of a personal level, what are the last three books you read or three films you watched, and enjoyed?

I don’t get to read that much in terms of novels. My literature is restricted to and often times I read, scientific papers, articles and books, more than anything else. Or papers that I am publishing.

So what about films – the last three you watched, and enjoyed?

More than likely on a flight. I don’t recall…

Perhaps on your way to or from Tucson?

One of the recent Marvel movies, quite like Wolverine too

So that genre is your preference! Our last question, is there anything else you’d like to say before we wrap up – how can readers get in contact with you?

Via our website (link). For general enquiries, email <info[at]> (link), for technical enquiries email <laboratory[at]> (link)

Swiss branch:
GGTL-GemTechLab laboratory
4bis route des Jeunes
CH-1227 Les Acacias, Genève
Franck Notari
Managing Director
Tel.: +41 (0) 22 731 58 80

Liechtenstein branch:
GGTL – GEMLAB Laboratory
Gnetsch, 42
LI – 9496 Balzers

Thomas Hainschwang
Managing Director
Tel.: +423 262 24 64