Teodora, the world’s largest cut emerald, which is the size of a watermelon, is set to go up for auction and is expected to fetch $1.15 million.

The 57,500-carat stone is scheduled to be auctioned off tomorrow by Western Star Auctions in British Columbia.

The gem was found in Brazil and cut in India, before being sold to rare gems dealer Reagan Reaney in Calgary, but there are doubts over whether it is in fact a true emerald.

“I’m positive it contains emerald but I’m not sure how much of it is emerald,” Jeff Nechka, the gemologist who appraised the stone, told JCK Magazine.

Jeff Nechka said that he cannot even confirm that the stone is in fact the “world’s largest emerald”.

The gem has been dyed so Jeff Nechka says it is possible that at least part of it could be dyed white beryl.

“It has been dyed to some extent but it’s impossible to tell the intensity of the stone prior. It’s impossible to know how much of it is emerald.” Jeff Nechka told JCK.

Director of Gemological Institute of America’s West Coast Identification Service, Shane McClure, said he had not examined the stone but that if there is any white beryl in the stone, GIA would likely term it “beryl with zones of emerald.”

“We probably would not call it emerald no matter what,” Shane McClure told JCK.

“They seem to think there is indication of natural green coloration but we wouldn’t call it emerald in any case.”

Teodora, the world's largest cut emerald, which is the size of a watermelon, is set to go up for auction and is expected to fetch $1.15 million

Despite the doubt, Jeff Nechka said that he was confident the stone has been priced accordingly.

“If it was solid, untreated emerald, you would be looking at 10 or 20 times the value for sure,” Jeff Nechka told JCK.

Regan Reaney, the Calgary gem wholesaler who is selling the stone, told JCK that anyone who questions the stone is welcome to examine it.

“This is 100 percent what we say it is. We know there is emerald throughout it, we don’t know how much. We know it’s not a total white beryl, but it has some white beryl in it. It’s not gem quality, and we know it’s commercial grade. But the size of it is what makes it special,” Regan Reaney said in the report.

If the stone is not sold, it will be sent to the Gemological Institute of America.

[youtube Bfo2HOeml5A]

[youtube VV7d1sFVxWc]