Cullinan V is an 18.8-carat heart-shaped diamond, the fifth-largest of the nine principal stones cleaved and polished from the Cullinan rough between 1908 and 1909 by Joseph Asscher & Co. of Amsterdam. Cut from what remains the largest gem-quality rough diamond ever recovered — the 3,106.75-carat Cullinan, found at the Premier Mine in the Transvaal in January 1905 — this stone occupies a singular place among the great diamonds of the British Royal Collection, distinguished both by its unusual heart-shaped outline and by its extraordinary optical purity as a Type IIa gem. It is mounted in a platinum brooch of scrolling openwork design and was presented to Queen Mary in 1910, entering a collection in which it has remained ever since.

The Cullinan Rough and Its Division

The Cullinan diamond was purchased by the Transvaal government in 1907 and presented to King Edward VII as a gift of loyalty from the newly self-governing colony. The task of cleaving and polishing the stone was entrusted to the Amsterdam firm of Joseph Asscher & Co., then among the most technically accomplished diamond-cutting houses in the world. The firm's principal, Joseph Asscher, undertook the first cleave on 10 February 1908 — a moment of such concentrated pressure that, according to well-documented accounts, he fainted immediately afterwards. The rough was ultimately divided into nine principal stones, designated Cullinan I through Cullinan IX, along with ninety-six smaller brilliants and a quantity of unpolished fragments.

The nine principal stones range from the 530.20-carat Cullinan I (the Great Star of Africa, set in the Sovereign's Sceptre with Cross) down to the 4.39-carat Cullinan IX. Cullinan V, at 18.8 carats, ranks fifth in this sequence and is among the smaller of the group, yet its heart-shaped form gives it an individuality that larger, more conventionally shaped siblings do not share to the same degree.

Physical and Optical Properties

Like all nine principal Cullinan stones, Cullinan V is classified as a Type IIa diamond — a designation indicating an almost complete absence of nitrogen impurities within the crystal lattice. Type IIa diamonds represent a small fraction of all gem diamonds and are prized for their exceptional transparency across a wide spectral range, their high thermal conductivity, and the particular quality of colourless brilliance they display. The Cullinan rough as a whole was remarkable for its Type IIa character, and this purity is transmitted fully to Cullinan V: the stone is of exceptional clarity, free of the nitrogen-related absorption that gives most diamonds a faint yellowish tint.

The dimensions of the finished heart-shaped brilliant are proportioned to display maximum scintillation while preserving the symmetrical lobes and pointed culet characteristic of a well-executed heart cut. The heart shape was a relatively uncommon choice for a stone of this importance in the Edwardian period; the dominant fashions of the era favoured old-mine, cushion, and early round-brilliant outlines. That Asscher's cutters selected this form for Cullinan V suggests a deliberate aesthetic decision, possibly influenced by the sentimental associations of the heart motif in the jewellery culture of the time, and perhaps by the particular geometry of the rough fragment from which the stone was derived.

The Heart-Shaped Cut: Historical Context

The heart-shaped brilliant is a modified pear cut in which the top of the outline is cleft to form two symmetrical lobes. Its origins as a distinct cut are traceable to at least the sixteenth century — a heart-shaped diamond is recorded in correspondence between Mary Queen of Scots and Queen Elizabeth I — but the form was never as prevalent as round, oval, or cushion outlines, partly because the cleft at the top demands exceptional skill to execute without creating optical dead zones or compromising the stone's structural integrity at its narrowest points.

In the early twentieth century, the heart shape carried strong romantic and dynastic connotations, making it an appropriate choice for a stone destined for a royal recipient. The Asscher cutters' ability to produce a heart of such precise symmetry and optical quality from a fragment of the world's most celebrated rough diamond stands as a testament to the firm's mastery. The cut has since enjoyed periodic revivals — notably in the later twentieth century — but has never displaced the round brilliant as the dominant form for important diamonds.

The Platinum Brooch Setting

Cullinan V is set in a brooch of platinum with a scrolling openwork design, a form entirely characteristic of the Edwardian and early Art Nouveau aesthetic that prevailed around 1910. Platinum had only recently displaced silver and white gold as the preferred metal for important diamond jewellery; its greater strength allowed settings of extraordinary delicacy, and its neutral colour provided no contaminating reflection to alter the diamond's apparent body colour. The openwork scrollwork of the Cullinan V brooch allows light to enter the stone from multiple angles, maximising the play of brilliance and fire that a Type IIa diamond of this size can produce.

The brooch is designed so that Cullinan V can be worn as a pendant as well, a versatility common to important royal jewels of the period. This dual function reflects the practical demands of royal ceremonial dress, in which a single piece might need to serve different roles across different occasions.

Acquisition and Royal Provenance

Following the completion of the cutting and polishing by Asscher & Co., the nine principal stones were returned to the British Crown. The stones were divided between the Crown Jewels — where Cullinan I and Cullinan II were incorporated into the Sovereign's Sceptre with Cross and the Imperial State Crown respectively — and the personal jewellery of the royal family. Cullinan V was presented to Queen Mary (then Princess of Wales, later Queen Consort to King George V) in 1910. Queen Mary was a passionate and knowledgeable collector of jewels, and the Cullinan stones she received — including Cullinan V, Cullinan VI, Cullinan VII, and Cullinan VIII — became among the most treasured pieces in her personal collection.

Queen Mary wore Cullinan V regularly throughout her long life, and the brooch appears in numerous official portraits and photographs from the first half of the twentieth century. On her death in 1953, her jewels passed to her granddaughter, Queen Elizabeth II, who inherited the full complement of Cullinan stones in Queen Mary's personal possession. Queen Elizabeth II was frequently photographed wearing the Cullinan V brooch, sometimes in combination with other Cullinan pieces, demonstrating the continued vitality of these stones as working jewels rather than purely archival objects.

Following the death of Queen Elizabeth II in September 2022, the jewels of the Royal Collection passed to the Crown and to the personal collection of King Charles III and Queen Camilla. Cullinan V remains part of the Royal Collection.

Relationship to the Other Cullinan Stones

To appreciate Cullinan V fully, it is useful to situate it within the family of nine principal stones:

• Cullinan I (530.20 ct, pear-shaped brilliant) — set in the Sovereign's Sceptre with Cross; the largest polished white diamond in the world.
• Cullinan II (317.40 ct, cushion-shaped brilliant) — set in the band of the Imperial State Crown.
• Cullinan III (94.40 ct, pear-shaped brilliant) — part of Queen Mary's Crown; now worn by Queen Camilla.
• Cullinan IV (63.60 ct, square cushion brilliant) — also from Queen Mary's Crown; frequently worn as a brooch.
• Cullinan V (18.8 ct, heart-shaped brilliant) — the subject of this article.
• Cullinan VI (11.50 ct, marquise brilliant) — presented to Queen Alexandra; now in the Royal Collection.
• Cullinan VII (8.80 ct, marquise brilliant) — pendant to a brooch with Cullinan VIII.
• Cullinan VIII (6.80 ct, oblong brilliant) — set in a brooch with Cullinan VII.
• Cullinan IX (4.39 ct, pear-shaped brilliant) — set in a ring.

Among these, Cullinan V is unique in its heart-shaped outline. Cullinan I and Cullinan III share the pear shape; Cullinan VI and Cullinan VII share the marquise. The heart form belongs to Cullinan V alone, giving it a visual identity that distinguishes it immediately from its siblings despite its relatively modest carat weight within the group.

Gemmological Significance

The Cullinan diamonds collectively represent one of the most important bodies of evidence for the properties of Type IIa diamonds at the very largest natural sizes. Type IIa material constitutes roughly one to two per cent of all gem diamonds by number, but its representation among the world's most celebrated stones is disproportionately high — the Koh-i-Noor, the Regent, and the Archduke Joseph diamond are all Type IIa. The Cullinan rough, at over three thousand carats, was an extraordinary example of this already rare material, and Cullinan V inherits its full optical and chemical character.

For gemmologists, the stone is also a reference point in discussions of the heart-shaped brilliant cut: its proportions, the execution of its cleft, and its optical performance under examination represent a benchmark from a period before modern computer-aided cutting optimisation, demonstrating that master cutters working by eye and experience could achieve results of the highest standard.

In the Trade and Public Consciousness

Cullinan V has never been offered for sale and, as part of the British Royal Collection, is not subject to commercial valuation in any conventional sense. Its significance in the trade is therefore primarily educational and historical: it is cited in discussions of famous diamonds, Type IIa material, and the history of diamond cutting. The brooch setting is frequently referenced in design histories of Edwardian platinum jewellery.

The stone is periodically displayed to the public, most notably at the Tower of London alongside other Crown Jewels and Royal Collection pieces, and at exhibitions devoted to royal jewellery. Its combination of historical provenance, optical purity, unusual cut, and royal association makes it one of the most discussed of the nine Cullinan principal stones after the two great stones set in the Crown Jewels themselves.

Further Reading

• GIA — The Cullinan Diamond
• GIA Gems & Gemology — Type IIa Diamonds