But you all knew that already.
The primary difference, according to Ron, is that Anodization is insulating, Iridite is conductive. Also when you think you mean Anodization, you really mean Iriditing.
To specify iridite, add to the drawing notes: "FINISH: IRIDITE PER MIL-C-5541, CLASS 1A"
There's Class 1A and Class 3. Class 1A is the rich-looking dark gold, Class 3 is called "clear" but is actually more like a chromate yellow.
All this and more are explained in this helpful forum posting on the difference between Class 1A and Class 3: http://www.finishing.com/4400-4599/4558.shtml
