Since a big chunk of playerbase always looking to trade gems/runes, maybe its a good idea to provide ingame mechanics for that; BH Jeweller Shop can be a good place for this.
inv
You are carrying:
a Diamond
a Emerald
a Ruby
lots
______________________________________________
Lot # | Bidder | Wants | Offers |
______________________________________________
1 | Splork | a Diamond | a Ruby |
______________________________________________
2 | Teker | a Emerald | a Rhodocrosite |
______________________________________________
3 | Breeze | a Jacinth | Pink Garnet |
______________________________________________
bid 2
Jeweller the jeweller takes your a Emerald and hands over a Rhodocrosite to you in exchange.
Then after, Teker issues "check" and Jeweller give him what was exchanged.
inv
You are carrying:
a Diamond
a Rhodocrosite
a Ruby
(Emerald disappeared, Rhodo added instead)
lots
______________________________________________
Lot # | Trader | Wants | Offers |
______________________________________________
1 | Splork | a Diamond | a Ruby |
______________________________________________
3 | Breeze | a Jacinth | Pink Garnet |
______________________________________________
(lot 2 disapperead since transaction was successful)
The exact command not nessesarily must be 'bid' but something else; trade (already used), exchange (already used), need to invite new one that is not in use.
Can extend to Offers two options that work "OR", so when player does "bid 2" they will need to add "op1" or "op2" keywords, like this:
_______________________________________________________________________
Lot # | Bidder | Wants | Offers option 1 | Offers option 2 |
_______________________________________________________________________
1 | Splork | a Diamond | a Ruby | a Malachite |
_______________________________________________________________________
2 | Teker | a Emerald | a Rhodocrosite | a Opal |
_______________________________________________________________________
3 | Breeze | a Jacinth | Pink Garnet | a Zircon |
_______________________________________________________________________
bid 2 op2
Jeweller the jeweller takes your a Emerald and hands over a Opal to you in exchange.
Can extend even further by adding "Wants" op1 / op2 AND at the same time "Offers" op1 / op2.
This way one player can exchange 2 gems he has to 2 gems he wants, in any combination. Maybe too complex.
As for actually consigning gems, dont have any ideas about how to enumerate gems/runes as we do with prices in coins...