THAT AINT A ROCK! IT'S A BOULDER!

This isn't a rock - it's a boulder.
An auction at Christie's next week will feature the Annenberg Diamond, a 32-carat dazzler that could fetch between $3 million and $5 million.

"The Annenberg outshines any other," said Rahul Kadakia, head of the jewelry department at Christie's, which is putting the gem on the block Wednesday morning.

"You have to consider how many there are in the world. Out of 100 million [rough diamonds] there are only 600 that finish between one and two carats. This one has 32."

It once belonged to Leonore Annenberg, a philanthropist who, along with her husband, Walter, donated billions to education and the arts.

She bought it in Los Angeles in 2007 for her 90th birthday and when she passed away earlier this year, her family decided to donate the proceeds.

"A part of her spirit is in this ring," said Kadakia. "It has elegance, prominence and it's the best one can have in a diamond. The symmetry, the precision, the color and the shape are all perfect. It has everything."

There are some less pricey baubles for sale with the Annenberg, including the Taj Mahal emerald expected to go for more than $800,000 and an 18-carat diamond necklace designed by Harry Winston that could bring $700,000.