Value of a stone is dependent on many factors, among them are the
famous 4 C’s (Color, Carat weight, Clarity and Cut); also dependent
on what gem the stone is. You did not specify if these are rough,
cabochon or faceted stones. That said, you could search the internet
and find stones that are similar and base you price on them. Most
other jewelers will expect you to sell to them at wholesale (usually
about 50% of retail price). You will find a huge difference between
stone dealers for what they charge. I recently investigated
purchasing some CZ stones for a customer (she specified CZ) and for
the same 12x6 marquis, I could pay from $1.66 to over $200 depending
on what company I went with. I chose the reputable company that I
have done business with for several years (the $1.66 folk,
wholesale).
look up their value and availability now - if they are rare or
irreplaceable make your decision based on that criteria. If the sale
of them means you won’t be able to make something you planned on with
the remaining pieces then you have to factor that in as well!
if you have many and don’t mind parting with some and they were
cheap- sell them but include any taxes, VAT,duties/customs, etc.
that you had to pay to get them to your studio- not necessarily
suggesting making a profit unless you think that is fair given the
material and its replace-ability.
Bottom line the person should pay at least what you paid for them.
From what I gleaned you are suggesting taking a loss because it was
’long ago"- some mines are closed, some materials no longer in
production so their value may be many times what it cost years
before-…If the friend wants them though, perhaps its because he
cannot get them anywhere else, or in a similar grade or cut. so you
need to do a bit of homework and maybe check your old invoices. Don’t
take a loss unless you want to make it a gift of sorts and money is
no object between you and your friend, or if you simply don’t think
you’ll ever use them. someone gave me some positively horrid stones
once that i can’t get rid of : they are not a cut I would ever
consider using, and I haven’t found a buyer for them either- nor
anyone else that has expressed any interest in them even free.
Perhaps your stones are similar, in which case giving them away may
be the best way to eliminate them from your “overstock”…
it’s not only taste, but cut, colour, quality, replacement sourcing
and will it eliminate your being able to use the remaining like
stones in one of your designs, or as a replacement for a piece you
made that may need a new one reset at some point, , do what you feel
is best after your researching their rarity (though if it’s a common
stone and abundant and you’ll never use the quantity you have in a
lifetime, then let them go; no research needed!)