Double-yolked eggs are reasonably common for ducks and chickens, despite the fact that we so rarely see them in stores. It is estimated that 1 in 1,000 eggs (out of 50 billion produced annually in the US) have double yolks. Eggs increase in size as the number of yolks increases, but most of them are caught by "candling," or holding the egg up to a light source to reveal a shadow of what is inside the shell, and used for other egg products instead of being mixed in with single-yolks. Stores that do offer the eggs usually have one local source for them. The chickens, ducks and other birds that lay them have a genetic tendency to produce the eggs, so if a farm is stocked with such birds, most of their eggs with have double yolks. The eggs are popular with anyone who likes yolks and are also believed to be good luck by many.

Far less common are multiple yolk eggs, including triples and quadruples, like the one pictured above. Apparently, the greatest number of yolks found in one egg was nine!

If you can't find any multiple-yolk eggs in your neck of the woods, you can always separate one egg, add the yolk to another, and save the white for later.

In China, eggs are sold by weight and their sale is often unregulated, particularly at local markets and in areas where the customers by large quantities at a time. Unscrupulous vendors have been known to pass off fake eggs to their unsuspecting buyers.

There are three types of faked eggs. The first are empty or cracked shells that are filled with soil. Since the eggs are sold by weight, a few soil-filled eggs in a crate will make it heavier and go unnoticed until it is too late. The second type of fake egg is the red-yolk egg. Because the redder yolks are considered to be more valuable and of higher quality, some egg-sellers feed their chickens very high quantities of food dyes, which causes them to produce red yolks without an increase in the quality of the egg or in the lifestyle of the chicken.

The most disturbing - though some might say disgusting - faked egg is the man-made egg.