Kommt auf das Material an, das entscheided auch unter welche Verzollungsgruppe der Schmuck fällt.

Packages whose declared value is under $200 ($100 if being sent as a gift to someone other than the purchaser) will generally be cleared without any additional paperwork prepared by CBP. However, CBP always reserves the right to require a formal entry for any importation and generally exercises this option if there is something unusual about the importation, or if important documents such as an invoice or bill of sale do not accompany the item. http://www.cbp.gov/xp/cgov/trade/basictrade/internetpurchases.xml

Stell ihm eine Rechnung aus über den exakten Preis der Ware und lege sie der Sendung bei.