The Beau Sancy diamond is one of the most unique and historically significant diamonds in the world. With a history that dates back over 400 years, this diamond has played an important role in Europe’s political and artistic spheres.
The History of the Beau Sancy Diamond
The Beau Sancy diamond, sometimes referred to as the Little Sancy to distinguish it from its larger sibling, has a long and fascinating history that dates back over 400 years. It is believed to have originated from the Golconda mines in India, which were renowned for producing some of the world’s most exceptional diamonds.
The diamond’s earliest known existence dates back to its purchase by Nicolas de Harlay, seigneur de Sancy, a French diplomat and collector of precious gems. In 1589, de Sancy faced financial difficulties while attempting to raise an army for Henry III of France, which led him to sell off some of his jewels, including both Sancy diamonds. It was after this sale that the diamonds received their names.

In 1604, the diamond was sold to French King Henry IV. The diamond then became part of the French Crown Jewels and was worn by Marie de Medici, the Queen of France, at her coronation in the Basilica of Saint-Denis in 1610. Her coronation portrait by Frans Pourbus the Younger displays the Beau Sancy diamond set into the top of the crown adorned with pearls and diamonds.
Shortly after Henry’s assassination, Marie assumed the role of regent for her nine-year-old son Louis XIII. However, due to her mismanagement and involvement in political intrigues, Louis exiled her in 1617. After fleeing to Cologne in 1630, Marie remained in exile until she died in 1642. Despite her mounting debts, Marie managed to retain ownership of the Beau Sancy diamond. However, the diamond eventually had to be sold to cover her funeral and other expenses.
An Amsterdam gem dealer sold the Beau Sancy diamond to Frederick Henry, Prince of Orange, for 80,000 florins. Despite being a significant expense, the purchase was considered a bargain since court jeweller Thomas Cletcher valued the diamond at over 150,000 guilders. Frederick Henry intended to present the diamond as a gift to his new daughter-in-law, 10-year-old Mary, Princess Royal, who was the granddaughter of Marie de Medici and daughter of Charles I of England.
The Beau Sancy diamond remained with the House of Orange for several years, but in 1659, Mary pawned it to support her brother Charles II in his attempt to regain the English crown for the House of Stuart. Following the success of the Restoration, Mary went to London to join her brother, but she passed away in 1661 before being able to redeem the Beau Sancy or retrieve her other jewellery from England.
Amalia of Solms-Braunfels, Mary’s mother, took up the task of reclaiming the Beau Sancy and resolved the issue by arranging for her grandson William III to marry Mary, daughter of James II. The two were then crowned as joint monarchs of England in the Glorious Revolution of 1688, making the Beau Sancy a part of the Crown Jewels of the United Kingdom for the duration of their reign. When William III passed away in 1702, the diamond returned to the House of Orange, as the couple had no children and Mary had predeceased him in 1694.

Frederick I of Prussia claimed the Beau Sancy diamond in 1702, considering it a cornerstone of the Prussian Crown Jewels. It passed down to his son, then to Frederick the Great, who gave it to his wife, Elisabeth Christine. The diamond was reset in the Rococo style as a bouquet jewel and featured in a painting by Antoine Pesne as the centrepiece of an elaborate pink bowtie.
The Beau Sancy diamond stayed with the House of Hohenzollern for 179 years, surviving the Napoleon invasion and witnessing the rise of the kings of Prussia to become German emperors. It was reset several times as a pendant, traditionally worn by royal brides. The diamond was last worn by Empress Augusta Victoria, wife of Wilhelm II. During World War II, it was hidden in a crypt and found by British troops after the war. The diamond was occasionally exhibited, and in 1972, it was displayed in Helsinki with its sibling diamond, the Sancy, after being separated for 370 years.
In 2012, Georg Friedrich, Prince of Prussia, put the diamond up for auction at Sotheby’s. Despite an estimated value of $2-4 million, a fierce bidding war occurred among five potential buyers, ending with an anonymous purchaser acquiring the stone for $9.7 million. Since then, the Beau Sancy has not been displayed publicly.
The Beau Sancy Diamond Characteristics

The Beau Sancy diamond is renowned not only for its rich history and political significance but also for its beauty and uniqueness. It is considered one of the most important diamonds in the world due to its exceptional size, colour, and cut.
The diamond weighs 34.98 carats and measures 22.78 x 19.58 x 10.98 mm. It has a faint brown colour (K) and SI1 clarity. Its unique modified pear double rose cut is also notable, with 58 facets that allow it to sparkle brilliantly in the light.
The diamond’s cut and shape are believed to have been created by a master craftsman in India in the 16th century. This unique cut is characterized by its unusual proportions, which include a flat culet and a high crown, giving it a distinctive and elegant look.
The Beau Sancy’s size and rarity have made it a highly sought-after diamond throughout history. Its journey from the Golconda mines in India to Europe, passing through the hands of kings, queens, and nobility, is a testament to its enduring value and beauty.
The Current Ownership of the Beau Sancy and Its Value Today
The ownership of Beau Sancy diamond has changed hands many times throughout its long and illustrious history. Today, the diamond is privately owned by a collector whose identity has not been publicly disclosed. The diamond is not on public display, and its current location is unknown.
The exact value of the Beau Sancy is difficult to determine due to its unique status as a historical artefact and a piece of fine jewellery. Its value is likely to be influenced by factors such as its provenance, rarity, and condition, as well as the current state of the global diamond market. However, its rarity and unique cut make it a highly sought-after diamond among collectors and investors.
The Beau Sancy remains an important cultural artefact and a symbol of European history and diplomacy. Its unique beauty and historical significance continue to inspire fascination and awe among those who appreciate fine art and jewellery.
Featured image: Heleashard / Wikimedia Commons