What is the Carmen Lucia Ruby?
By Jared James · Last updated 21 May 2026
Definition
The Carmen Lucia Ruby is a 23.1-carat Burmese ruby and one of the largest faceted rubies in the world, housed in the National Gem Collection at the Smithsonian Institution in Washington. It is a step-cut stone of exceptional colour, displaying the deep red known in the trade as pigeon's blood, and it was mined in the Mogok Valley of Myanmar. The ruby was donated to the Smithsonian in 2004 by Peter Buck as a memorial to his wife Carmen Lucia.
Frequently asked questions
- Where is the Carmen Lucia Ruby kept?
- It is on permanent display at the National Museum of Natural History in Washington DC, part of the Smithsonian's National Gem Collection alongside the Hope Diamond and other famous stones.
- How big is the Carmen Lucia Ruby?
- It weighs 23.1 carats, which makes it exceptionally large for a faceted gem-quality ruby. High-quality rubies above 5 carats are already rare; finding one of this size with the colour and clarity of the Carmen Lucia is extraordinarily unusual.
- What makes a Burmese ruby so valuable?
- Burmese rubies from the Mogok Valley, in what is now Myanmar, have long been prized for their intense, slightly fluorescent red colour described as pigeon's blood. The combination of that unique hue, the origin and the stone's natural fluorescence under UV light makes top Mogok rubies the most sought-after and expensive in the world.
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