Get to know Hayley Jeannel de Thiersant: ESG Lead at Hill & Co.

At Hill & Co. we specialize in growth solely within the diamond, gemstone, and jewelry industry.

Clients say working with us is like having the ultimate little black book of industry contacts ready to help at any time. Our team is ready to provide you with proactive advice and creative solutions to every challenge that comes your way.

As an organization, we embrace the phrase, “Stand on the shoulders of giants,” and our collective strength and accomplishments are built on the unique expertise and contributions of our individual team members.

Over the coming weeks, our newsletter will introduce you to our team and give insight into the powerhouse individuals driving growth for your business at Hill & Co.

Introducing Hayley Jeannel de Thiersant

Meet Hayley Jeannel de Thiersant, ESG Lead at Hill & Co., and expert in the jewelry industry with over 13 years of experience spanning diverse areas of our industry, from gemological lab, merchandising and design, to strategy.

Beginning her career in a boutique in Seattle, Hayley then worked for 5 years at Ben Bridge, building expertise in Quality Control and Digital Merchandising while also studying at GIA and earning her degree as a Graduate Gemologist.

She then moved on to become Special Order and Custom Jewelry Program Manager with Blue Nile, where she first met Hill & Co. CEO and Founder, Elle Hill as a colleague.

The meeting, then her later move to Europe, led to the launch of Hayley’s journey as part of our team,  3 years ago.

As Hill & Co.’s ESG Lead, Hayley partners with leading industry organizations to develop and grow their sustainability projects. She also works with clients to craft ESG strategies that showcase their commitment to responsible practices.

Hayley is leading Hill & Co’s. internal ESG projects and advocates for the positive impacts of social and environmental projects undertaken by our team.

Join us now as Hayley shares her career journey and insights on sustainability in our industry.

Sitting down with Hayley

So, Hayley, where did your career in jewelry begin? Do you remember when and how your passion was ignited?

 “I initially pursued a BA in English Literature.  After teaching English abroad for two years in Prague, I found myself back in the States, ready for my next move. It was then I discovered my love for jewelry while working at a tiny Seattle boutique on the waterfront. Under the guidance of a female mentor, who ran her own shop, I learned the foundations of running a successful retail operation.

“Though I had a good amount of knowledge about stones, it wasn’t until then that I realized I could make a career as a gemologist.”

What do you love about jewelry?

 “There’s something so special about each piece of jewelry – we are just its custodians for a short time before passing it on.

“My love for jewelry started when I was young, with glimpses of my mom’s off-limits jewelry box. She’d sometimes pull out her collection for me to admire, and we’d sit on her bed together while she shared stories of who gave which piece to her and what the different stones meant.

“This storytelling and the beauty of the jewelry itself, combined with the human artistry, has always connected with me.”

When did you start to explore the origin and sourcing of each individual piece?

 “Jewelry and gems connect us to the past, present and future. I’m a naturally curious person, and I’d imagine when, how and where the stone was formed.

“From this inherent curiosity, I started to explore and learn more about source countries and what goes into procuring a stone.

“Customers are starting to ask more questions also. They want to know where the products they buy originate. But that’s just the beginning. As an industry we have to work together to have a positive impact across the supply chain.”

 Can you tell us a little more about your role with Hill & Co. and the projects you are involved with?

 “As the Lead Consultant for ESG Projects at Hill & Co., I work with leading industry organizations on how to grow the scale and influence of their ESG projects. We also work with companies who are newly prioritizing sustainability to define their goals and build their strategy, so that they can speak with confidence to the actions they are taking to align their business with their core values and create measurable change.”

Sustainability is now a key concern for consumers around the world. What do you think suppliers, brands, designers and retailers need to do in order to show their commitment – and active contribution to – sustainability?

 “What gets measured gets made. To make real progress across the supply chain we’ve got to move from general commitments to measured progress using data, science-based targets, and reporting to show real results. We already measure KPIs when it comes to margin, turn-over, page-views and clicks; we need to approach our sustainability efforts with the same desire for real-time information: to know what is and is not working in their sustainability strategy in order to address it and find the areas of greatest opportunity for improvement.”

 In your opinion, how prevalent is ‘greenwashing?

 “Although companies are becoming more conscious of the need to prove the ESG claims they make, it’s still not unusual to see very loosely founded, or occasionally completely unfounded, claims made by diamond, gemstone, and jewelry companies.

“Whether intentional or not, unsupported claims create confusion for customers. It poses a risk, as clients often trust companies’ claims at face value.

“Even though consumers research products more thoroughly these days, it’s not their responsibility to verify a statement’s accuracy, intent, or falsehood. When greenwashing is exposed, it creates distrust, which has far-reaching negative impacts for our industry.”

 Is there anything that you think needs to change at an industry level to increase transparency and honesty when talking about sustainability?

 “We’re at a turning point in our industry where we have the opportunity to standardize how we talk about sustainability. My hope is that we can work collaboratively across organizations and international borders to agree on acceptable terminology that will engender trust, with both retail clients and in B2B transactions.

“Industry-wide we need to bring sourcing communities closer into the conversation. We need to be willing to ask difficult questions and listen to what sourcing communities need for improved safety, well-being, and economic opportunity. Ultimately to increase transparency and honesty we have to start by being honest with ourselves and acknowledging our blind-spots.

“Only then can we address them and move from a position of “do no harm” to “create positive impact.”

Thank you for sharing your industry insight, we’d love to know a little more about you.

Favorite book?

“I’m currently reading two books. I have The Great Believers on my nightstand, which is a poignant tale of the AIDS epidemic in the ‘80s intertwined with a woman’s search for her daughter in Paris, who has joined a religious cult.

“I’m also reading Women in the Viking Age. My husband and I recently visited the Natural Museum of Denmark, Copenhagen, which sparked my interest with the Vikings, particularly the women of the era, who we rarely hear about.”

Favorite museum?

“Wow, it’s difficult to choose. The Louvre holds a special place in my heart since my time living in Paris. I would often explore a wing for hours on end. However, the British Museum had a similar impact on me when I visited. I’ve also loved the collections at smaller museums, such as the Seattle Art Museum. If I had to choose, the Louvre would win, as I could easily see myself spending a lifetime there.”

 Is there a particular piece that stands out?

“I’d have to say the jewelry at the Louvre. Sadly, a significant amount of it was lost when the monarchy was abolished, and much of what remains is from the Napoleonic era.

“I also enjoy the ancient Roman aspects and learning about Tribal France. Seeing the vestiges of the Roman occupation is a highlight.”

Can you tell us something about yourself that people may not know?

“If I wasn’t a gemologist, I’d be an archaeologist. The opportunity to connect with the past, but also use discoveries to inform the future.

“It reveals that we are more alike than we think. While it’s true that we are always striving to improve, we are still all human. We have to be careful not to create divides based on lifestyle, geography, or era when we share so much in common.

“I’m thrilled that I get to indulge my passion for archaeology in August when I go on a dig in Spain – a program I have long since wanted to take part in.”

 And finally, what excites you about the future of Hill & Co.?

“As I pass my third year at Hill and Co. I reflect on the immense growth that I’ve witnessed in the company. One thing that sets us apart is the culture. It may sound cliché, but working alongside the individuals in my team and with exceptional clients is a constant source of inspiration which fuels my enthusiasm day after day.

“I’m excited to see how the team will grow further in the future and to be a part of our evolving culture.”

The diamond, gemstone and jewelry industry is an ever-evolving space, constantly reshaped by changing trends and technologies.

These new challenges demand a fresh approach to many aspects of your business.

Whether you are ready to launch a new line, acquire new buyers, increase your bottom line revenue, scale rapidly or penetrate new markets, our team can help you achieve your growth goals.

If you would like to explore working with us, it all starts with a conversation.

Reach out to us today at

All the best,

Rosie Wareham

Chief Marketing Officer





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