I have the iPhone 7 and so not too sure about macro or micro or any special features for this camera.
It gets the job done. I wonder if it will zoom in closer likely using touch gestures like piching two fingers together or spreading apart.
I use an iPhone 6S and I get the best results when zoomed in half way and then just moving the phone as close to the coin as I can while still getting a clear shot. Using it fully zoomed in gets too blurry. The iPhone 7 has a stronger lens so it may be different.
You know without pix of coins, nobody believes your 6S will take a pic! ;-) I'd love to see, I do Apple naught since the UI makes my addled brain hurt. The 7 results are quite impressive.
These are iPhone 6S shots. The other trick is experimenting with the lighting. But the photos are completely unedited. They're not perfect, you'll notice that the 2017 is clear but Liberty is a bit blurry.