Famous Diamonds, Rarity & Mines
The Moussaieff Red Diamond: Why It Matters
The Moussaieff Red is a 5.11-carat natural Fancy red diamond cut in a modified triangular brilliant form. It is widely recognised as one of the largest known diamonds graded with red as the dominant colour. Public accounts trace the rough to Brazil in the 1990s, after which the polished stone entered the international market and was acquired by Moussaieff Jewellers. Its importance comes from the extreme rarity of natural red colour, its unusual size and its recognised laboratory documentation. Any public price or value figure should be treated as historical context rather than a current appraisal. A famous red diamond is not a direct comparable for another stone unless colour, size, cut, clarity, provenance and transaction circumstances are genuinely similar.
What Defines the Stone
The Moussaieff Red weighs 5.11 carats and has a modified triangular brilliant cut.
Its colour is described as Fancy red, a category for which GIA generally does not use the usual Light, Intense or Vivid progression.
Its size is exceptional within the very small population of documented natural red diamonds.
Discovery and Market History
Published accounts connect the rough diamond with Brazil and the 1990s.
The polished stone was previously known as the Red Shield before its acquisition by Moussaieff.
Details repeated in secondary accounts should be distinguished from the laboratory facts recorded for the stone.
Why Red Diamonds Are So Rare
Red colour is associated with structural distortion in the crystal lattice and is closely related to the mechanisms behind pink colour.
Most natural red diamonds are very small.
Even minor purple, orange or brown influence can change the formal colour description.
Price and Value Limitations
Historic transaction figures are frequently repeated, but they do not provide a current market appraisal.
Named stones can carry provenance and publicity that ordinary candidates do not share.
A seller should not use the Moussaieff Red to guarantee the value or appreciation of another red diamond.
What Collectors Can Learn
Exact report wording matters more than an informal label such as vivid red.
Large size transforms rarity in an already scarce colour category.
Documented identity and ownership history are central to the significance of a famous stone.
What This Means for a Private Buyer
Treat the Moussaieff Red as a benchmark for rarity, not as a direct pricing tool.
Use the Famous Diamonds, Rarity & Mines hub, the guide to rare diamond colours and the natural green diamond guide for broader context. Pelican can evaluate documented rare-colour candidates through private sourcing.
Frequently Asked Questions
How large is the Moussaieff Red Diamond?
It weighs 5.11 carats.
What colour grade does it have?
It is known as a natural Fancy red diamond.
Where was the Moussaieff Red found?
Published accounts connect the rough with Brazil.
How much is the Moussaieff Red worth?
Historic figures are not a current appraisal; the stone is singular and rarely comparable.
Why is it so rare?
Natural red colour is exceptionally scarce, and the stone is unusually large for the category.
Is Fancy Vivid red a GIA grade?
GIA generally uses Fancy red rather than the usual intensity progression for red diamonds.
Private acquisition