the Smithsonian Institution sells nearly 36-carat diamond for $ 7.1 million . Amount said to be highest price for a diamond sold at auction . the Archduchess Maria Amalia was mined in Spain 1673 .
Christie 's sells nearly 36-carat diamond for $ 24.3 million . Amount said to be highest price for a diamond sold at auction . Jewel was mined in India nearly 400 years ago .