Rare historic gems - Emperor Maximilian Diamond and the Catherine the Great Emerald and Diamond Brooch will be offered at Christie's New York sale slated for April 22, 2010. Both gems carry a historical legacy that defines them priceless and both have not been displayed in public for decades, reports say.

The 39.55 carat cushion-shaped Emperor Maximilian Diamond was owned by Archduke Maximilian in 1860, and passed through royal hands, and through private sales to jewellers. It appeared at a Christie's auction in July 1982, and was purchased by Laurence Graff for $726,000 - more than twice the estimated price of $330,000. Further, Graff sold it to Madame Imelda Marcos, wife of the president of the Philippines. After many such private transactions, it was acquired by the present owner and it will appear in public for the first time at Christie’s forthcoming auction, since 1982. The gem is estimated to fetch between $1 million to $1.5 million at the auction.

Catherine the Great Emerald and Diamond Brooch, centers on a hexagonal-cut Colombian emerald of exceptional quality weighing between 60 and 70 carats. The emerald is set with rows of rose and old mine-cut diamonds and is mounted in silver-topped gold. The jewel is remarkable for its quality and size. Originally it was owned by Catherine II of Russia, who ascended on the throne in 1762. The brooch was passed through the royal and noble treasures. An American buyer bought the brooch in 1972, whose estate is offering the jewel at the forthcoming Christie’s auction, and the jewel will appear on sale for the first time in nearly 40 years. The brooch’s estimated sale price is between $1 million to $1.5 million). The viewing of Christie's New York sale will take place at Christie's Rockefeller Center Galleries between April 17-21, 2010.