I have trouble with the last part of the following sentence, starting from the last 私 (bolded):
(I've left the original furigana; source: http://www.aozora.gr.jp/cards/000291/card47785.html )
Is the な in 「神秘的」なと云う the attributive marker for the na-adjective 神秘的? It would make sense but I always thought you had to have a full clause before という (not just the attributive form of a na-adjective). As I understand it, this particular instance seems to be quoting from the girl's repertoire, as if saying "in her own words, she would call it mysterious."
Also, I am a bit confused as to what is being qualified here since 云う, 愕くべき and 上品な are all in their attributive form. I'm reading it as 愕くべき上品 ("a wonderful elegance") and simiarly 「神秘的」なと云う上品 ("one that could be called mysterious"), but please correct me if I'm wrong. (By the way, is there a reason why 云う is not in the continuative form? Both 上品 and 言葉 already have qualifiers in the attributive form so I thought a second qualifier should come in the continuative form.)
Tentative (rough) translation: From her work, I learnt words whose surprising elegance could be called "mysterious."