5 minutes with… A diamond ring and a pendant brooch by JAR

‘To have two important JAR pieces such as these in one sale makes for a very special auction,’ says Daphne Lingon, Head of Jewellery at Christie’s in New York, of a diamond ‘thread’ ring and a gem-and-diamond pendant brooch by Joel Arthur Rosenthal. On 17 April, both pieces will be offered in the New York Magnificent Jewels  sale at Christie’s.

Born in New York City in 1943, Joel Arthur Rosenthal graduated from Harvard in 1966 before moving to Paris. After a brief period in the film industry he opened a needlepoint shop, where his clients included designers from Hermès and Valentino. After working with Bulgari in New York, he returned to Paris and in 1977 opened a store in the Place Vendôme with his partner, Pierre Jeannet; his initials, JAR, were the only source of identification on its façade.

Today Mr. Rosenthal’s imaginative, meticulously-crafted jewels are renowned worldwide. JAR produces only 70 to 80 designs each year, in the house’s signature unique settings and unexpected colour combinations, often inspired by the natural world.

The first of the two privately consigned JAR jewels offered at Christie’s on 17 April, the ‘thread’ ring, is set with an elongated, oval-cut diamond weighing approximately 22.76 carats that is D colour, VVS1 clarity and Type IIa. The stone sits within a diamond-set two-tiered threadwork gallery and hoop, mounted in platinum.

‘JAR is well-known for the complexity and intricacy of his “thread” designs,’ Lingon explains. ‘The fine pavé work beautifully showcases the stone, which is itself extraordinary in size, colour and quality. The mounting holds the diamond securely, but there’s also a certain lightness to it. The designer’s ability to create this sense of balance is quite a feat.’

Previously, the piece was a highlight of the 2006 Magnificent Jewels  sale at Christie’s in New York. Offered from The Collection of Ellen Barkin, it achieved $1,808,000 —well over its high estimate of $1,200,000.

Also offered in the 17 April sale is a multi-gem and diamond ‘Moghul’ pendant-brooch, executed in 1999. The top, designed as a stylised bombé architectural turret, is pavé-set with circular-cut amethysts. At its centre is a cushion-cut sapphire of approximately 14.77 carats, within a border of single-cut diamonds; a pearl tassel is suspended from its single-cut diamond cap. The brooch features a detachable neck-chain set with single-cut diamond stations, and the reverse is decorated with single-cut diamonds.

‘The pendant is not one we’ve seen at auction before,’ says Lingon. ‘It is a fantastic example of Rosenthal’s exemplary workmanship — the quality is exceptional. The central cushion-cut sapphire, an untreated stone from Sri Lanka, gives the piece a beautiful burst of blue on a background of amethysts. You then have a wonderful, fluid drop of graduated pearls — something JAR is known for, but that you don’t always see in jewellery today. So there’s a beautiful sense of movement.’

Also key, adds Lingon, is the intricate pavé diamond work on the reverse side of the piece. ‘It's just as beautiful from the back as it is from the front. This is really done just for the wearer — no one else is going to see the detail. The fact that everything has been thought of and executed so beautifully is another hallmark of JAR’s work.

‘To some extent, words can’t describe what Rosenthal achieves in his jewels,’ Lingon continues. ‘His colour combinations and shapes are so unexpected, as is the use of unusual gemstones. While he is inspired by 17th, 18th and 19th-century pieces, his designs are always marked by his unique vision. You’re always a bit at the edge of your seat, wondering what he’ll come up with next.’

All proceeds from the sale of the pendant-brooch will benefit the Arts for Justice Fund. Started by Agnes Gund in participation with the Ford Foundation and Rockefeller Philanthropy Advisors, the initiative connects criminal justice advocates with artists to address the crisis of mass incarceration in the United States.