Jewelry is ALMOST ALWAYS a bad investment. Who appraised it?? Take it to a pawnbroker, or a jeweler who buys this stuff. See if they'll buy it for $2400, or for that matter even $840.
No. It's not even an investment.
If it was appraised by the person selling it, you need another appraisal. Buyer beware!
No. It's probably a scam.
Would you buy a 14k white Gold diamond ring that has been appraised for $2400 for $840 even if you don't have a girlfriend ?