Ian Russell, 13th Duke of Bedford, and his third wife, Nicole Russell, Duchess of Bedford, who wears the family amethysts in a portrait taken at Woburn Abbey, ca. 1970 (Central Press/Hulton Archive/Getty Images)

February is the birthstone month of the glorious purple amethyst, and today’s sparkler, the Tavistock Amethyst Tiara, features some of the largest amethysts you’ll ever see in a diadem.

Central Press/Hulton Archive/Getty Images

This piece has a two-step creation story. The largest amethyst and its surrounding diamond honeysuckle setting came first, made sometime around the 1830s. Around 1870, that piece was integrated into a new tiara, featuring grape leaves and more large grape-colored amethysts.

Keystone/Hulton Archive/Getty Images

The tiara is part of a large parure, which I think evolved over the course of the Victorian era, much as the tiara did. You’ll note that the bracelet matches the design of the tiara, with a trio of amethysts set in diamond grape leaves. The ring (which is worn here stacked with a diamond ring) is set more simply, with a large amethyst ringed by a slender cluster of diamonds.

Nicole Russell, Duchess of Bedford wears the amethysts, January 1968 (R. Powell/Daily Express/Hulton Archive/Getty Images)

The brooch and earrings from the set echo the setting of the ring…

Nicole Russell, Duchess of Bedford wears the family amethysts, ca. 1970 (Keystone/Hulton Archive/Getty Images)

…and the necklace as well, which is very typical of the first half of the nineteenth century in its design. Both the necklace and the brooch feature a briolette amethyst drop, which looks especially incongruous with the necklace. (I’d image the drop was not originally part of the necklace’s design.)

Nicole Russell, Duchess of Bedford (second row, left) wears the amethysts at the State Opening of Parliament, 1969

The moving image above comes from the State Opening of Parliament in 1969. You’ll spot the amethysts on the left side of the image; the Duchess is seated just above Princess Margaret. It’s striking to see just how much the tiara sparkles in motion.

It’s not entirely clear which member of the family had the piece made. The earliest pieces from the suite were probably made during Lady Georgiana Gordon’s tenure as Duchess of Bedford. Her husband, the 6th Duke, was made a Knight of the Garter in 1830. In 1870, the title was held by William Russell, the 8th Duke of Bedford, but he was never married and would therefore probably not have had any need for a tiara. Perhaps it was the cousin who would succeed him, Francis Russell, who had the piece made? Or maybe it was Francis’s son, George? After all, George became the Marquess of Tavistock (that’s the subsidiary title of the Bedford dukedom) when his father inherited the dukedom in 1872. The tiara and its accompany parure take their name from the Tavistock title — that might be the biggest hint we have.

Nicole Russell, Duchess of Bedford wears the amethysts, ca. 1970 (Central Press/Hulton Archive/Getty Images)

Exact provenance aside, the tiara is a lovely piece with a clear symbolic meaning. The overall effect of the grape leaves and the wine-colored stones is that of a tribute to Dionysus, the god of wine — which makes perfect sense, as the word “amethyst” roughly translates to “not intoxicated” in the original Greek. The Greeks believed that those who wore the stone were protected against drunkenness; medieval Europeans thought that wearing amethysts protected you from fits of bad temper. (Really the same thing, I suppose.) Today, the piece is still owned by the family, and I assume each marchioness and duchess in the last century who has worn it has done so proudly, calmly, and (ahem) soberly.