What is this object?

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Question 14: What is Dr. Oz holding?
A) A kidney stone
B) A gallstone
C) A ganglion cyst
D) A ball joint from the ankle

The correct answer is B.

Dr. Oz says gallstones can come in a variety of different colors and shapes, depending on what substances they contain, such as red blood cells or cholesterol. "They're made from different materials, because your gallbladder cleans a lot of material out," he says. While some are round, Dr. Oz says others form in the shape of dice if they are pushed together.

While he says larger gallstones are not dangerous, the smaller ones can cause problems. "They actually travel into the main duct that drains your liver, and they can block off the pancreas and the liver. That's when you turn yellow and get pancreatitis," he says. "So these things, although they're beautiful, can be dangerous."