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The Portuguese Diamond

The 127 carat Portugese diamond fluoresces blue under ultraviolet light.

The Portuguese Diamond weighs 127.01 carats. It’s near flawless clarity and unusual octagonal emerald cut make it one of the world’s most magnificent diamond gems. It is perhaps more than a little surprising, then, that so little documented information exists about it’s origin and early history. The lack of an authoritative provenance has given rise to considerable legend. One legend was that it was discovered in Brazil in the eighteenth century and became part of the Portuguese Crown Jewels. There is no documentation, however, that substantiates a Brazilian origin or connection to Portuguese royalty, nor is it clear where or from whom this story originated. The diamond most likely was found at the Premier Mine in Kimberly, South Africa, early in the 20th century. .

One part of the diamond’s history that is well-documented is that in February 1928 Peggy Hopkins Joyce acquired the diamond from Black, Starr & Frost. She traded a $350,000 pearl necklace for the diamond and $23,000 in cash. According to New York newspaper accounts, it was mounted on a diamond-studded platinum choker to be worn close around the throat. The jewelry firm’s spokesperson indicated that the diamond was found at the Premier Mine, Kimberly, South Africa, in 1910, and that the firm had obtained it shortly after its discovery. Miss Joyce was dazzling blonde who performed in the Ziegfeld Follies, a true glamour girl of the 1920s. Sometime prior to 1946 Miss Joyce placed the diamond on consignment to the group of jewelers mentioned above, in an unsuccessul attempt to sell it.

Harry Winston acquired the Portuguese Diamond from Miss Joyce in 1951, and for the next several years it traveled the country as part of his “Court of Jewels” exhibition. In 1957, Winston sold the diamond to an international industrialist, who then traded it back in 1962. In 1963, the Smithsonian acquired the Portuguese Diamond from Mr. Winston in exchange for 2,400 carats of small diamonds.

The Portuguese Diamond strongly fluoresces blue under ultraviolet light. A soft fluoresence is visible even in daylight or artificial light and gives the stone a slight bluish haze, enough so that it was once advertised as the “largest blue diamond in the world.” In fact, if not for the fluorescence, the diamond would appear slightly yellowish. SOURCE: The National Gem Collection by Jeffrey E. Post.

I have a variety of beautiful diamonds that you may want for yourself or a loved one. If you are considering purchasing, please contact me. Since 1991, I have helped thousands of couples select diamonds and diamond jewelry. Contact me at or call me at Gallery of Diamonds in Santa Ana, CA. 800-667-4440.

The stone now resides in the Smithsonian Institute on permanent display in Washington DC.

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