The so-called diskette is a flat black square of rather tough plastic with a hole in the middle and an oblong slot on each of the flat sides; it is said to be 5 inches square, but that is a  as the only person who probably ever measured one of these things, I can tell you it is 5 3/16 inches square; that may seem irrelevant, but it is only the beginning of the Great Deception.
The item called a diskette is made of plastic.