To be honest, I found this article a little cringe-worthy. I'm going to pass along some of the tough love passed down from my professors. Mineralogy is the study of minerals. Metamorphism does not change "the study of minerals", it changes the mineral assemblage.
Sometimes scientists will use the terms mineralogy, or geology, to refer to the mineralogic or geologic features of a rock or region. It's acceptable, but you will always run into someone who will call you on the use of the word.
There's more, but I don't want to get into it. Seeing mineralogy used that way just made me cringe. Proof read before you post!