This is a sucker effect where the Magician explains the how of the trick, then ends with a climax implying  real magic
Performer shows a colored handkerchief in his hand.  He rolls it between his hands, and it changes into an egg.

He now explains that he actually uses a hollow egg with a hole in it.  When he rolls the silk between his hands, he pushes it inside the egg through the hole.  He repeats the performance to demonstrate this.

Now, comes the real Magic !  He makes a Magic pass over the egg and it changes into a real Egg ! He breaks the egg into two pouring out the yolk and white. We supply you the special plastic egg and a colored silk handkerchief.