Frieder Lauer, Houston
First Place, Colored Stone Distinction
First Place, Custom Design Distinction
By John Shanahan
You can’t ignore the 51.28 carat ametrine at the center of Frieder Lauer’s award-winning ring—and not just because of the intricate cut or the stunningly sharp delineation between the ring’s dual hues. It’s because that’s exactly what the client for this custom piece wanted: to showcase the stone, and nothing else. Oh, and make this considerable rock work in a ladies’ size 6.
The stone first caught Lauer’s eye when Brian Gavin, a longtime friend and CEO of Brian Gavin Diamonds, brought him five large stones cut by renowned lapidary artist John Dyer. Gavin had a client who wanted a custom ring for his wife, and it was to feature one of the stones. The customer was open and undecided about which, so Gavin asked if Lauer would meet with the customer and discuss some possibilities. But right there in his shop, Lauer already knew which stone he wanted to work with.
“Right away, it was one of my favorites,” he says of the ametrine. He knew its dimensions were a challenge for a small finger size, but the cut was intricate, and its colors were astonishing. “It has one of the sharpest delineations between the yellow and the violet I’d ever seen. Usually with ametrines, there is a fade-out where the colors change. In this stone, it’s striking how John managed to get this sharp delineation right along the center line.”
Of course, the final decision was the customer’s. But that didn’t mean the jeweler couldn’t campaign for his personal candidate. “I pre-sorted them based on my preference so I’d have something to say in the final choice,” Lauer says. “When we met, I explained which stones I thought had the most potential.”
The customer agreed that the ametrine was the right stone, and then dropped something of an aesthetic bomb on Lauer. He wanted a solitaire. Anything the jeweler did was to be in service to the stone. “And then he told me, ‘I want it to appear to float above my wife’s finger. Can you do that?’”
Lauer had not pictured the stone as a solitaire. In fact, it took a while for him to align his design ambitions with such a restrictive idea. Luckily, he had another issue that would eat up some time first. “When a stone is this big, I prefer to design the setting in CAD because it gives me more control over the details,” he says. “First, I needed an accurate digital model of the stone. Because it’s such a one-of-a-kind gem, I couldn’t just send it in somewhere to have it sprayed with a non-reflective coating and then 3-D scanned. I had to resort to taking accurate photos of all the gem’s sides, and then rebuild the stone as a virtual model.”
Using Rhino CAD software, Lauer imported the photos and used them to trace a network of curves over each image from every viewing angle. He did this one dimension and one facet at a time, taking exact physical measurements with a digital caliper, then transferring those to the software, refining every line as he went along. When he had a CAD model he was satisfied with, he printed it. Knowing he needed a 1:1 match between the real stone and its digital counterpart to accurately create the setting in CAD, he pressed the ametrine into softened thermoplastic compound. “When the compound hardened, I had the ametrine’s ‘footprints,’” he explains. “Now I could try to fit my 3-D–printed model into these footprints and see where model and gem matched and where they didn’t.”
Using this process, Lauer went through three revisions of his stone model, and spent about 40 hours overall creating it.
Banking on his “trust credit,” Lauer forged ahead with only sporadic communication throughout the process. To create the ring and setting in CAD, he encased the digital gem in a virtual box matching its volume and dimension. “I stuck a cylinder through this box to represent and help visualize the target finger size for the ring,” he says. “Then I started cutting away from this bulky mass until there was just enough left to hold the stone in place.” Freed to follow his own judgement while making something unobtrusive and minimal, Lauer relied on his years of experience as a setter for knowing “when to say when.”
The final design has an architectural essence reflecting the jeweler’s aesthetic. “The stone is bulky, so I wanted something suggesting lightness or motion underneath it,” he says. “That way, if someone looks beyond the stone, they see movement. I wanted to have lines that swooped toward the stone, so it was not a bulk held by a block.”
For setting, Lauer built four large prongs as seamless extensions of the body of the ring, maximizing a clear view of the gem while holding it secure. The prongs’ job was assisted by what Lauer describes as “crosshairs”—deep grooves Dyer had cut into the bottom of the stone along its x and y axes. Correlating ridges in the ring’s shank were designed to fit into those grooves, locking the stone into its proper alignment.
The customer was ultimately presented with two design choices that were similar in principle but different in level of detail. While Lauer was prepared to realize either, he once again got to have a vote. “He asked me which one I preferred. His wife initially liked the more radically plain option, but I said I was partial to this fluted one, and he agreed. I’m glad he did!”
With the decision made, Lauer cast the ring as a single piece in a 950 platinum/ruthenium alloy that would offer strength and holding power. “It’s the only alloy I would have dared to make this setting in,” he says. Platinum’s density and its superior resistance to hardening during cold work allows it to be bent without cracking or snapping out of its intended final position—a crucial consideration for the secure and firm setting of such a big stone.
Was the customer happy with the end result? You might say they were floating on air.