If you are searching for the big floating silver coins that appear above certain NPCs when they die, you should look here.
Silver Coins are items used as a universal currency for the trading system. You can use these coins to buy and sell items from traders, and to hire units to fight or farm for you.
All traders and captains hold a silver coin in one hand to show that they are selling something, but the coin is not dropped if they are killed.
Obtaining coins
Coins can be obtained in a number of ways:
Crafting
The simplest way to get silver coins is simply to make them yourself. Mine silver ore from the ground, smelt it into ingots, craft the ingots into nuggets and then into silver coins. This method originally produced only 2.25 coins per silver ore, but as of Beta 24, this value has been changed to one coin per silver nugget, or nine coins per silver ore.
Trading
Of course, you can also earn coins from trading. Selling items to any of the traders or travelling merchants in Middle-earth will earn you coins - however, you may need a certain alignment level to trade with a certain trader. Different traders also buy different items, which can be seen in their inventory screen.
If you manage to obtain 1000 silver coins in a single trade, you'll earn yourself the achievement "Filthy Rich". The recommended way of getting this achievement is to trade a lot of gold to a Blacksmith of Gondor or Rohan. Dwarven Merchants occasionally buy gold as well.
Looting
Chests in many structures have a chance to contain a number of silver coins.
Killing
Several humanoid NPCs also have a chance to drop coins as a semi-rare drop along with their usual drops. The amount can vary. The NPC's that drop the most silver coins are Bandits (between 12 and 28), so heading to a biome where bandits are frequent can be a good way to make money – provided that you see the bandits before they take your stuff!
Questing
Completing a mini-quest will almost always reward you with some coins, in addition to some alignment to the faction that you complete the quest for.
Coin Exchange
As of Public Beta 22, it is possible to exchange silver coins for more valuable coins, once you've accumulated ten or more. In order to do this, speak to any items trader, select "Exchange Coins", and put the coins you want to exchange in the middle slot. You will then be able to exchange one type of coin to the equivalent value of another type of coin.
Fractions of a coins cannot be obtained from exchange, therefore, you must have at least 10 smaller coins to change them into a bigger coin. When you change bigger coins to smaller ones, you can only change a maximum of 6 at once, because 7 would leave you with 70 smaller coins, which is more than a full stack (64). In both cases, what is left from the exchange stays in the middle slot.