flabbergasted

as if struck dumb with astonishment and surprise; "a circle of policement stood dumbfounded by her denial of having seen the accident"; "the flabbergasted aldermen were speechless"; "was thunderstruck by the news of his promotion"

ताज की खूबसूरती देख दंग रह गए स्टीफन !

The mill - owners were even more flabbergasted.