Ülle Limbach, Head of Metrosert’s Assay Office, would have never thought that she would one day work in the world of jewelry. Just a few years ago, she was organizing controlled explosions at the Tallinn Zoo to boost children’s interest in science.
Today, however, she uses expensive equipment to examine what jewelry is actually made of, helps people identify the value of old items, and encounters the touching stories of the tested objects every day, stretching back through generations.
“I like to investigate and find out what is truly inside an object; it feels a bit like detective work,” Ülle says.
The task of the Assay Office, which is part of Metrosert, is to verify the compliance of precious metal products with standards, analyze alloys to determine their composition, and, if necessary, hallmark jewelry with a national control mark. It is here that they check whether a piece of jewelry actually contains the precious metal and in the quantity promised by its marking.
Saw Her New Job in a Dream
The role of Head of the Assay Office actually came as a surprise to Ülle. She had worked at Metrosert for four years as a metrologist, dealing with the calibration and measurement of measuring instruments. Her desk saw pH meters, oximeters, breathalyzers, viscometers, and other devices on whose accuracy the daily measurements of laboratories and companies depend. When the Assay Office was merged with the physics-chemistry field of the metrology division last year, she was offered the position as head of the unit.
“I essentially had three weeks to absorb all the knowledge needed for the job from the Assay Office’s legendary head, Jelena, who had decided to make a career change. The beginning was quite difficult because the world of precious metals was completely different from what I had done before. But I didn’t panic—I actually enjoy jumping headfirst into unknown waters a bit.”
Although the new role was unexpected, she admits that she somehow anticipated the change. “It sounds unbelievable, but before the structural change, I once saw in a dream that I was working at the Assay Office. I told a colleague about it, so the idea wasn’t entirely foreign to me.”
The decision to continue in the new role was made easier by the fact that she was surrounded by familiar colleagues with whom she greatly enjoys working.
“I like that we have very similar people together—educated people who work towards a common goal, based primarily on science, justification, and substantive discussion. Opinions are not just pulled out of thin air, but are based on knowledge and analysis. You don’t have to constantly prove yourself here regarding why you think something. When something is discussed, it is based on how things truly work from a metrological or scientific perspective.”
Old Love Doesn’t Rust
The new role allowed her to return to her main specialty, chemistry. According to Ülle, her relationship with chemistry could by no means be called “love at first sight.” School chemistry was not an easy subject for her at all. “I don’t know if it was the teachers or the materials at the time, but the problems were difficult, and I didn’t fully understand it. But I liked the practical side. I had a solid four in chemistry at school, but I still had to work hard for it.”
As a child, she had dreamed of becoming a lawyer—a strong sense of justice and a readiness to stand up for herself still show signs of this today. When entering university, an area called environmental protection and technology caught her eye, hoping it would lead to a career that would allow her to work as a developer or implementer of environmental regulations.
“Once I started studying, however, it quickly became clear that it wasn’t romantic nature conservation, but a very technical and extensive curriculum. We studied industrial processes, filters, membranes, pumps, and systems that make various production plants work. Alongside chemistry, there was a lot of engineering thinking, and at times it all seemed very complicated. But by then, I had grown so close to my classmates that changing majors seemed out of the question!” she admits with a laugh, adding that shared study sessions, partying, and a shared good sense of humor helped create a bond of friendship that lasts to this day.
Explosive Days at the Zoo
Ülle’s career has spanned very different fields—but whether in the food industry, a biodiesel plant, or a pharmaceutical laboratory, the core of her work has always been chemistry. “Production environments have always been the most captivating for me—I like processes, seeing how some material or substance eventually becomes something that people actually use,” she said.
The most unexpected stop on her journey was the nature education department of the Tallinn Zoo. Her days were spent welcoming school groups, and her evenings conducting chemistry hobby groups for children.
“Children, of course, liked it best when something exploded,” she recalls with a laugh. “For example, we would cut sodium and drop water on it, which caused a small explosion. The ‘elephant toothpaste’ experiment was also very popular, where thick foam rushed out of a glass tube with great force.”
She admits that sometimes the experiments became a bit more lively than originally planned. “Once, a table caught fire. And we managed to trigger the fire curtains multiple times. Then soon after, there would be another call from the security guard asking, ‘Doing experiments again, right?’” Ülle recalls.
For older students, she tried to link the experiments to what was in the school chemistry textbooks, so that complex topics would become more understandable and better remembered.
“Sometimes I miss that time,” she admits. “I liked the children’s spontaneous emotion and how they were truly thrilled by new knowledge. But it was also exhausting, of course,” she confesses.
Objects Have a Story
At the same time, work at the Assay Office is anything but dry and technical. A very large part of her daily routine involves communicating with people who bring various items in for testing. Along with the objects, their owners’ very personal stories reach her as well.
“People bring us old family jewelry, rings of deceased relatives, or objects whose value has been an assumption rather than knowledge for decades.”
These stories are not always easy, because sometimes testing brings the realization that items considered valuable are not so at all.
“Once, during testing, a heavy lump of metal was brought to us, about which there had been a belief in the family for half a century that it was tableware melted together during the bombing of Tallinn. In the end, the analysis showed that it was just a large piece of tin. In such moments, you feel a bit sorry for the person, because you see that the value of this thing lay not so much in the metal as in the legend that accompanied it,” Ülle admits.
Cases where a person comes to test their valuable item because they have decided to sell it due to severe financial difficulties also cause sadness. “When it turns out to be just ordinary silver-plated metal, it is very difficult to deliver that message to the person.”
In addition to jewelry, watches, medals-orders, coins, and gold bars, very different pieces of metal reach the Assay Office, which Ülle affectionately calls “chunks”. According to Ülle, the most tedious material was metal residue granules coming from inside electronic devices. “Sometimes people bring really unexpected things here,” she says. “Recently, for example, we tested a gold tooth.”
Testing Brings Clarity
The Assay Office also frequently provides answers in disputes. For example, a jewelry seller recently had to make new wedding rings for a bridal couple because a test proved that the wedding rings, which had caused an allergy, contained nickel alongside gold.
“One manufacturer brought us earrings for inspection that had begun to turn dark and smudge after a couple of weeks of wear. The customer suspected that the problem was in the alloy, but our test showed that the alloy fully complied with the hallmark. In the end, it turned out that because the customer wore the earrings 24 hours a day without taking them off, the silver and copper contained in the alloy had begun to oxidize. Reaching such knowledge was a learning point for both the jewelry owner and me,” Ülle confirms.
According to her, people could know more about precious metals—she doesn’t even dare to think how much precious metal people throw away after the death of their elderly relatives, thinking they are cheap trinkets. Before starting work at the Assay Office, she herself treated hallmarks quite superficially, but now she sees very clearly why such a system is necessary and how much actually depends on trust.
“Some cheap imported jewelry may look very high quality on the outside, but analysis reveals that different details contain different alloys or even metals harmful to health. When you see this world every day, you become much more attentive yourself; you start to notice quality, materials, and how things are actually made.”
Always Looking for Beauty and Quality
This attentiveness follows her outside of work as well. In recent years, sewing has become her major hobby, which started from a purely practical need—her tall son could not find suitable sportswear in stores, so she had to learn to sew them herself. For four years, she has participated in a sewing circle, which has also sparked a serious interest in fabrics, patterns, and quality materials.
Today, she sews her own dresses, works with highly temperamental silk fabrics, and looks at clothes in second-hand shops with a completely different eye than before. “I immediately look at the material, the seams, and assess how well something will hold up,” she says. “I like beautiful and well-made things.”
Her creativity is also expressed in soap making, which she has been doing for years. One might think that this activity is limited to making nice-smelling gifts for friends and acquaintances, but it has literally taken her very far.
“Thanks to my soap-making hobby, I was able to visit Rwanda this spring, where I taught local enterprising youth and adults how to make soap to help them find a source of income. Rwanda is a beautiful country, like one big botanical garden, but there is an awful lot of poverty there. Behind the project is a local school where practical skills such as sewing, woodworking, car repair, and much more are taught, which can help earn a dignified living.”
Ülle also loves to travel. Her journeys have taken her to Kenya, Zambia, and India in addition to Rwanda, but at the same time, she admits that countries like Spain, Portugal, and France are still undiscovered for her. “However, I would always go back to Italy,” she says. “There is something there that suits me very well—so much beauty and the local temperament, which reminds me a bit of myself,” she smiles.
Whether it is the next travel plan, a sewing needle, or a new soap recipe—Ülle has been constantly driven forward by curiosity. The very same curiosity that accompanies her today at the Assay Office, where every tested item can bring a new piece of knowledge, a surprise, or a story that has traveled through several generations.