Family name: Mizuichi
Olvian conch is part of the treasure called Merchant's Ring which reduces existing Market fees by 5%, and is needed to furthermore craft the Magnate's Ring
To get it, you will need to utilize your Merchantry skills and reach the Total Sold items of 1,5 billion 10 times. It does not need to be in consecutive days. So any day in the past you reached the goal will also count toward the future journey.
Like any treasure part it's something of a long play goal, so don't get discouraged if you can't start working toward it right away.
There are only 3 ways that count toward your Total Sold amont
1. Selling normal trade items in town
2. Selling speciality trade items in town (need to make profit on them)
3. Selling normal trade items to Morco, the wandering merchant
The items crafted from lightstones and orange gems that are sold to the wandering merchant won't count as profit in the last screen (though you obviously still profit on them, it just won't raise the Total Sold stat)
The easiest way to reach the 1,5 billion in sold items is to spend one day before in preparation for the run. If you collect all 15 types of normal trade items at 1600 each and fill the 12000 weight pool of the last Merchantry wagon, the next day will become a breeze to reach the needed amount, so in ideal scenario you will only need to spend 20 days with this method.
The speciality items are best to buy between Glish - Delphe Outpost - Florin as you can sell them in next town and always turn profit
The wandering merchant is not needed if you spend the day before in preparation, but if you want a little extra you can always pop up the orange merchantry potion and teleport to him directly (of course he can't be in a place too far away from your regular route, you still need food to visit most towns)
What's needed to succeed in this method is definietely the last merchantry cart that can store the weight of 12000 LT, the highest level of merchantry is probably not needed, but as you reach the higher levels it will be easier to reach a full towns route.
As always you can check the food in towns before you start the merchantry run, the more food you can get in towns, the easier it will be to reach all towns (beside Keplan). If you dont like the amount, you can restart the run. If you dont exit the town none of the food will be used to restart.
My preferred all towns route is: Behr --> Trent --> Behr --> Calpheon --> Epheria --> Florin --> Delphe Outpost --> Glish --> Heidel --> Western Guard Camp --> Veila --> Kusha --> Ruins Excavation Site --> Tarif --> Abun -->Altinova
And the back route: Altinova --> Abun --> Altinova --> Tarif --> Ruins Excavation site --> Kusha --> Veila --> Western Guard Camp --> Heidel --> Glish --> Delphe Outpost --> Florin --> Epheria --> Calpheon --> Behr --> Trent --> Behr
No need to emulate though, as long as you can reach most towns during the run the 1,5 billion Total Sold amount should be successful
After 10 runs the Olvian Conch will pop up in your achievements window
Happy experimenting and playing :)