Sorry, you can't remove those shiny marks. Think creatively, maybe put on that iron mark some clothing label that you like (or something like this: http://www.amazon.com/dp/B006Z0QVAC/?tag=lotoshth-... You will have a new look for your clothe for sure.
Note: it's always better if you turn your black clothing inside out so you'll be ironing on the reverse side. Lesson and learned. Time to move on.