(CNN)A "perfect" diamond said to be so large that it draws awe-struck people across a room has sold for $22 million at a Sotheby's auction in New York.
The 100-carat, emerald cut, D color, internally flawless diamond is the largest of its clarity and cut to ever be shown at auction.
"People everywhere have been drawn to it from across the room and they are in awe of its size, particularly when they put it on their hand," said Gary Schuler, the head of Sotheby's jewelery department in New York, before the sale. "They can't believe there's a diamond this pure of such impressive scale."
Only six flawless diamonds over 100 carats have ever been sold at auction, including the one sold on Tuesday, according to Sotheby's. The others include an 118.28 carat oval diamond that sold for $30.6 million at a Sotheby's Hong Kong auction in 2013, a record for a white diamond.
The uncut diamond weighed over 200 carats.
'Highly-important' diamonds
The massive gem led the house's Magnificent Jewels auction, which included a collection of Kashmir sapphire jewelery and several Art Deco pieces from Cartier. The entire collection, more than 350 pieces, raised more than $65 million -- a record for a jewelry auction at Sotheby's New York.
"It was encouraging to see the impact of private collectors throughout the day, including at the highest end of our sale: eight of our top 10 pieces were purchased by private individuals," Schuler said. Online buyers contributed "heavily" to the final total, he added,
Sotheby's said the demand for "highly-important" diamonds was evident in other lots. The second-highest price of the day was $3.3 million for a 22.30 carat diamond ring.
Diamonds classed as flawless -- free of internal defects under intense magnification -- are extremely rare, especially at larger sizes.
The rough diamond, which was mined by De Beers in southern Africa, originally weighed over 200 carats, and was carefully refined for more than a year before it got to its current size and cut.
"A classic emerald cut like this one allows for a wide expanse of pure material to be viewed without the distraction of a more complex facet arrangement," Schuler said before the sale.
"It's almost like looking at the glimmer of a reflecting pool."
