Sofie Boons, a U.K.-based jeweler-turned-scientist, recently received a flurry of media coverage when she announced she’d grown rubies in platinum mountings. Her discovery uses a flux solution as a growth agent and waste material as a “seed.” The resulting gems form in days, and the process purportedly requires far less energy than gems grown from scratch.

Here, Boons, a senior lecturer in design crafts and Ph.D. candidate at the University of the West of England in Bristol, tells JCK about what sets her method apart; whether it could be used to grow sapphires, emeralds, and diamonds; and her hope that one day every jeweler might grow their own gemstones.

How did you get started in this?

I was trained as a jeweler in Antwerp and moved to the U.K. for my studies, and I ended up working at the British Academy of Jewellery. In 2016 I had the opportunity to visit a gemstone-growing company. I realized I didn’t know much about crystal growth. I knew that there were lab-grown gemstones, but I was taught to just look at them [as synthetics]. When I saw the factory, I saw huge opportunities, and a lot of waste material that was being put to the side. It was too valuable to scrap but still not being used for anything else.

When I took on a Ph.D., one of the things I wanted to investigate was using waste materials. We’ve been growing rubies since the early 1900s, but there hasn’t been many innovations with those techniques.

I started this in a very DIY way, in my kitchen with sugar, salt, and alum, to understand how crystal growth works.

My process uses a furnace and a crucible. That’s not unique. What’s unique is this process uses low pressure and I can introduce pieces of jewelry into it. So I can plant a ruby seed into a ring and grow that larger in the piece. No one has ever done that before, as far as I’ve looked.

So it’s not a high-tech method.

No. It’s quite DIY. We have some changes to the setup—that will be published when the Ph.D. comes out.

Are the rubies set as rough?

I do not do any cutting to them. Because of the crystal structure, you get facets appearing. You could cut them afterward, but I prefer to celebrate their uniqueness.

Can people tell the difference between these growth-created facets and faceting done by cutters?

Some of my facets are so sharp it looks like I’ve done them on the faceting machine. But others will show certain small lines or natural-appearing patterns. Most people could probably tell the difference.

How do you prevent the furnace from damaging the mounting?

The temperature isn’t high enough to damage the platinum. As long as you ensure that your formula is low enough, you don’t damage the platinum piece.

 Could you do it with gold or silver?

At the moment, the formulas are higher temperature than the melting point of gold, but it is something I’m actively looking at, so we’ll see. Silver has an even lower melting point than gold, so that’s not something I immediately envision being possible. But gold is an ambition.

Is your method quicker than other processes?

Because I use waste material, if I have a big enough seed, I don’t need to grow [the ruby] from scratch. I just grow them larger. And because you have a starting material, the process doesn’t need to be as long as growing from scratch.

Is the waste natural or lab-grown material?

It could be anything. If it’s a small mined ruby and it’s been chipped and it would just not be financially viable to recut it, that’s a stone that’s no longer in circulation. That could be grown larger, rather than just sitting in storage.

But it could also be lab-grown waste, particularly in industry. There’s a lot of laser production, and the waste from those process would be useful too.

What’s the biggest ruby you’ve grown?

It was about 6 by 6 millimeters or so. But if you have a larger seed, or a larger crucible, you could do larger stones as well.

How about clarity?

I haven’t sent them to any labs, and that’s not my immediate intention. They aren’t perfect. Because they grow following the crystal structure, it’s a less controlled process than other growing processes. You get unique outcomes, which look more like natural rubies. That is exciting to me, as a designer.

Have you done this with other types of gems, such as sapphires, emeralds, or even diamonds?

No. I am looking into opportunities. I have a few collaborations in the pipeline.

Do you think that’s possible?

Yes. It’s all speculative at the moment, but I believe it’s possible, and I’m actively working on getting those things done.

Do you see other uses?

I’ve collaborated with a crystal grower who wants to [develop] glow-in-the-dark gemstones. We can add properties to these materials that are not possible in nature. That is something I’ve been investigating as a researcher and a designer.

Are you surprised no one else has tried this before?

It is surprising. I have a theory why that is. A lot of chemistry happens in chemistry labs, and that doesn’t necessarily involve collaborations with jewelers. There isn’t much crossover. I looked at these processes from a jewelry point of view.

Your press release mentions sustainability. As you may know, there’s a debate in the industry about how that word’s defined. Some are concerned lab-grown materials will  hurt people in developing nations who depend on mining revenue.

I’m not an expert on sustainability. I think people shouldn’t say all lab-grown gems are sustainable. You can grow gemstones and know the impact of them, because that’s a measurable process, but you still must want to know the impact, and you still have to put things in place to use the most sustainable materials, to reduce the growth time. If you don’t do that, then it would be greenwashing to call them a sustainable alternative. What’s unique about my process is my use of waste and reducing the growth time.

Why did you send out a press release about this—for funding?

Yes. As my Ph.D. comes to an end, it’s my intention to look for further funding and build partnerships with those who are interested in those techniques.

What is your larger vision?

My dream is that this process would become more accessible to jewelers, and that you could grow what you need, when you need it—more than it just being dominated by a few major players. It could become a creative technique, rather than just a chemistry technique.

(Photos courtesy of University of the West of England at Bristol; ruby rings photos by Sofie Boons)

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