The Case of the Pink Diamond

The day that Andrew solved the cobra case was only yesterday in the city of Oklahoma City, OK. His friend, Nicole, lived right next door to him. Since he has solved the case, he set up his own detective agency. The first customer that day was a kid named Jack Kiks. “I have a case for you.” said Jack.
“What seems to be the problem?” said Andrew.
“This kid said he has a pink diamond and that a pink diamond is the most valuable type of diamond there is.”
“What is the kid's name?” asked Andrew.
“The kid is named Don Monymaeker.” said Jack. “He's planning to sell it to the highest bidder at the school.”
“Let's go.” said Nicole. “It'll be fun.”
So the group went to the school and found a crowd of kids gathered there. In the middle of the crowd was Don. He was about to make his speech. “Come, one and all!” said Don. “Prepare to be amazed! You are the luckiest kids in the world to see the first pink diamond! I will show you the most valuable diamond there is!”
He pulled the diamond out of the box the he had held it up to the sun. The kids saw their reflection in the diamond. “I am starting the bid at one dollar!”
Before the kids started bidding, Andrew said, “Don't waist your money. It's a fake!”
Why did he say that?

Leave your guess in the comments and I'll post the answer tomorrow evening!

Bobo