The Woyie River Diamond was recovered on 6 January 1945 from the Woyie River near Koidu in eastern Sierra Leone. The uncut stone weighed 770 carats (154 g), and at that time it was the largest alluvial diamond ever found, and the third largest diamond discovered in Africa, after the Cullinan Diamond and the Excelsior Diamond.
| Weight | 770 carat (154 g) |
|---|---|
| color | D-flawless |
| Country of origin | sierra leone |
| Discovered | 1945 |
The alluvial Star of Sierra Leone, discovered at the Diminco mine in Sierra Leone in 1970, is larger at 968.9 carats (193.78 g) uncut.
The uncut Woyie River Diamond had a broad lozenge shape, measuring 71 × 53 × 32 millimeters (2.8 × 2.1 × 1.3 in), with one unusually flat cleavage plane. The rough diamond was brought to London, where it was viewed by Queen Mary in October 1947 and then exhibited at the British Industries Fair in May 1949.
The stone was cut by diamond cutters Briefel and Lemer in London (who also cut the Williamson pink diamond) into 30 gems weighing 282.36 carats (56.472 g) in total, including 10 of over 20 carats (4.0 g) each. The largest of the gems is the Victory Diamond which weighs 31.35 carats (6.270 g) and is Emerald cut (occasionally described as “step cut”).
