De Young Red Diamond

Mistaken for a Garnet

The diamond was acquired by Boston jeweler S. Sydney DeYoung while it was mounted in an estate scarf pin. Because of its dark brownish-red appearance, the stone was believed to be a garnet.

Red garnets were commonly used in antique jewelry, so there was little reason at first to suspect that this particular stone was something dramatically more rare.

DeYoung eventually examined the stone more carefully and recognized characteristics that did not seem consistent with garnet. Further examination established that the mysterious reddish gemstone was, in fact, a natural diamond.

S. Sydney DeYoung Recognizes Its Importance

Once DeYoung understood what he had discovered, the stone took on an entirely different significance. Natural diamonds displaying a predominantly red or reddish body color are among the rarest varieties of colored diamonds.

Rather than immediately offering the extraordinary stone for sale, DeYoung removed it from its jewelry setting and kept it securely in his vault.

The diamond eventually became known as the De Young Red Diamond in recognition of the Boston jeweler who discovered its true identity and preserved it for future generations.

The De Young's Extraordinary Color

The De Young has traditionally been called the De Young Red Diamond, although modern gemological terminology provides a more precise description of its color.

The Smithsonian describes its GIA color grade as natural Fancy Dark reddish brown. Its appearance is therefore considerably darker and more brownish than the vivid red coloration seen in some other celebrated red diamonds.

This distinction is important because modern GIA grading standards reserve particular terminology for diamonds whose predominant body color meets specific requirements. Nevertheless, the De Young remains one of the world's most historically significant large natural diamonds with a strong red component.

The origin of red coloration in natural diamonds is especially interesting to gemologists. Rather than simply resulting from a chemical coloring element, red coloration is believed to be associated largely with structural changes or deformation within the diamond crystal lattice.

Preserved Rather Than Sold

One of the most unusual aspects of the De Young story is what happened after its identity became known.

Instead of treating the diamond simply as valuable merchandise, DeYoung retained it. According to the Smithsonian, he kept the stone in a vault and never offered it for sale.

That decision ultimately helped preserve an important gemstone for scientific study and public exhibition.

A Gift for Future Generations

DeYoung ultimately decided that the extraordinary diamond should become part of the Smithsonian Institution's National Gem Collection.

The stone was given to the Smithsonian through DeYoung's estate and was formally accessioned into the National Gem Collection in December 1987.

Its Smithsonian catalog number is NMNH G9871.

From Estate Jewelry to the National Gem Collection

The journey of the De Young Red Diamond is remarkable: a dark reddish stone once mistaken for garnet became one of the most important colored diamonds preserved by the Smithsonian Institution.

It is now part of the National Gem Collection at the Smithsonian's National Museum of Natural History in Washington, D.C., where it can be studied alongside some of the world's most significant diamonds, gemstones and mineral specimens.

The Smithsonian continues to classify the De Young as one of the largest known natural diamonds displaying this exceptionally rare reddish coloration.

Why the De Young Red Diamond Is Famous

The De Young Red Diamond is famous not simply because of its size. Its importance comes from the combination of several extraordinary characteristics.

It is a large natural colored diamond displaying an extremely uncommon reddish body color; it has an unusually high VS2 clarity grade; its discovery story began with a gemstone mistakenly identified as garnet; and its owner chose preservation and public legacy instead of selling the stone commercially.

The result is a gem whose story connects the worlds of antique jewelry, gemological discovery, diamond science and museum preservation.

What once appeared to be an ordinary reddish stone in an old piece of jewelry has become an enduring part of America's National Gem Collection.