The economist had an expert opinion on how to oversee gold.
chop / seal
one's seal or stamp with one's name on it, which the Japanese use instead of signatures.
a field guide
a field guide; a book where each page has one picture and a description of a thing. (birds, gandams, monsters, doinks, whatever).
to have a 'discriminating eye' for art. To appreciate art or music on some deep, expert level.
expert opinion. Like an American Idol judge or art critic or some guy in court who says that tobacco does/does not cause cancer.