www.cbp.gov/xp/cgov/newsroom/news_releases/local/2013_nr/may13/05142013_3.xml

Inlaid mother of pearl is also a no-no.

For a very thorough article try the link below:

TEASER

" Suppose that you simply did not know that the bridge was Madagascar rosewood? Or, you knew that it was Madagascar rosewood, but had been told by a credible source, like its manufacturer, that it had been harvested from the legal regions of Madagascar. The penalty is forfeiture. Yes, that's right. The Lacey Act imposes what the law calls strict liability. Even if you have no knowledge, "

www.fretboardjournal.com/features/magazine/guitar-lover%E2%80%99s-guide-cites-conservation-treaty

Sincerely,
Gargoyle

ignorance is no excuse. Yeah, I've been questioned many times (good stories about why)
and also searched (down to socks in underwear immediately before boarding in Germany) and had illegal agricultural products seized.   And paid extra duty on cotton. And had to plug in and play an instrument at boarding check. It is part of travel, if it frightens you GOOD, please stay at home.