Regent Diamond
Regent Diamond
The 140.64-carat cushion-brilliant Type IIa diamond at the heart of the French Crown Jewels
The Regent Diamond is a historic 140.64-carat cushion-brilliant diamond of exceptional colour and clarity, held permanently in the collections of the Musée du Louvre as part of the French Crown Jewels. The stone was discovered at the Kollur mine in southern India around 1698, cut in London between 1704 and 1706 from rough of approximately 410 carats, and sold to the French Crown in 1717 by the East India Company governor Thomas Pitt — for which reason it is also known historically as the Pitt Diamond. As a gemmological object, the Regent is a Type IIa diamond of near-colourless body and very high clarity, the standard against which other historical Indian diamonds of comparable size are measured.
Origin and rough
The Kollur mine, located on the Kistna River in the former Golconda kingdom, was the principal source of the great historical Indian diamonds. Surface alluvial workings active from at least the early seventeenth century supplied the rough that became the Koh-i-Noor, the Hope, the Orloff, and the Regent, all of them Type IIa or near-Type-IIa stones. The original Regent rough is reported by contemporary accounts at approximately 410 metric carats — extraordinary for the period — and was acquired by Thomas Pitt while he was governor of Madras for the East India Company in 1701 or 1702.
Cutting
Pitt sent the rough to London for cutting in 1704. The cutter Joseph Cope took two years to produce the principal stone of 140.64 carats, accompanied by a small number of cleavage pieces and minor stones — some of which were sold to the Russian Crown and one of which is reputed to have been incorporated in the Romanov regalia. The yield from the original rough was thus approximately 34 per cent, a normal figure for a substantial high-quality Indian rough cut to the standards of the early eighteenth century. The cushion-brilliant cut produced is high-crowned and broad in plan, with a relatively shallow pavilion that was the convention for cutting at the time.
Optical properties
The Regent is a Type IIa diamond — chemically pure, free of significant nitrogen impurity, and consequently of exceptional colour and clarity. Modern Type IIa stones of comparable size and origin are graded D to E in colour and Internally Flawless to VVS in clarity by GIA standards; the Regent is widely accepted to fall within this range. Type IIa diamonds constitute approximately 1 to 2 per cent of natural diamond production worldwide and are characteristic of the finest historical Indian diamonds. The stone's adamantine lustre, full cushion-brilliant scintillation, and the modest blue fluorescence sometimes associated with Type IIa diamonds combine to produce an optical performance that, even by modern standards of brilliant cutting, ranks among the finest of any historical stone.
Provenance
The Regent has remained continuously in the French national collections since its sale to the Regent of France, Philippe d'Orléans, in 1717. It was set successively in the coronation crown of Louis XV, in ceremonial pieces during the reigns of Louis XV and Louis XVI, in the pommel of Napoleon's coronation sword in 1804, in tiaras and diadems during the Restoration and Second Empire, and finally as a stand-alone display object since 1887, when the Third Republic excluded it from the sale of the Crown Jewels and assigned it permanently to the Louvre. The continuous documented provenance is itself a substantial part of the stone's value as a historical artefact.
In the trade
The Regent is excluded from commercial circulation. For the trade, however, it functions as a published reference for Type IIa cushion brilliants of large size — a continuously displayed and extensively documented stone against which any new appearance of comparable historical material can be evaluated. When Type IIa Indian-origin stones of significant size appear at auction, comparison to the Regent and to the small group of comparably documented historical diamonds is the standard frame of reference.