NEW YORK >> A “perfect” 100-carat diamond in a classic emerald-cut is going on the auction block where it could fetch between $19 million to $25 million.

Sotheby’s will offer the white diamond on April 21 in New York.

It’s an internally flawless D color stone, which the auctioneer said is considered “perfect.”

Sotheby’s New York jewelry department head Gary Schuler likened the stone’s transparency “to a pool of icy water.”

“This 100.20-carat diamond is the definition of perfection. The color is whiter than white. It is free of any internal imperfections,” he said in a statement.

The stone is the only classic emerald-cut white diamond of the highest color and clarity and over 100 carats to come to auction, according to Sotheby’s.

The diamond was mined in southern Africa within the last 10 years and weighed over 200 carats before it was cut and polished, the auction house said.

The owner wished to remain anonymous.

Only five “perfect” diamonds over 100 carats have sold at auction in the last 25 years, with a 118-carat oval-cut stone fetching $30.6 million at Sotheby’s in 2013. It set a record for a white diamond.

A record for any diamond is $46 million for a 24.78-carat emerald-cut pink stone, set at Sotheby’s in 2010. It also set a record for any jewel at auction.