I'd respectfully suggest that unless she knows a great deal about
emeralds you advise her to leave the entire idea alone.
Emeralds are notoriously difficult stones to dabble in and there are
so many different scams out there that buying from a reputable dealer
at market price where you return the purchase if it turns out to be
fake or fraudulent is the only way to go. Even then you will not be
able to sell back the material that you buy at a profit. The
sell-back is always less than the investment because dealers have to
make a percentage. Even after you keep them for years the inflated
value would not increase that much more, if at all, than putting the
money in a bank and accruing interest.
Stones can crack, loose color, split, turn out to be tourmaline,
glass, dyed, painted, fused, synthetic. Unless you test, and have the
skill to do it well, you're heading for a disaster.
Buy stones because you love them, want to own them - because they
thrill, delight and make you sing - for the joy!
It's the same thing with gold. It's not really an investment item -
except as part of a much larger portfolio.
"Gold at cost" never is! You'll pay for the workmanship and more in
an inflated price for the stone. There is no such thing as a free
Gold and Stone