Silver Seated Liberty dollars, which were struck from 1840 through 1873, were designed by Christian Gobrecht.

How much are the Seated Liberty dollars worth?

That is, most U.S. coins are intended to be used for trade within the United States. for goods and services.

The 19th-century silver U.S. Trade dollar, which was struck from 1873 to 1885, is a coin quite unlike the coins that most U.S. collectors are used to seeing.

The Trade dollar was a coin intended for exchange, export, and circulation purposes within Asia -- China in particular.

Here's everything you want to know about U.S. Trade dollars...

A coin's grade is absolutely key when determining how much a coin is worth -- given its date and demand.

When you grade a coin, you actually are paying more attention to how much wear a coin has rather than how it looks overall. That's because wear is the key factor in deciding what grade a coin is.

The coin grading system is rather complex. It could take a whole glossary of grading terms just to get to know the ins and outs of coin grading. And it may take years of experience to be able to take one look at a coin and assign it an on-the-spot grade.

For starters though, here are some examples of coin grading criteria:

• An uncirculated coin must have absolutely no wear -- not even evidence of rub on its highest point (like Lincoln's cheek on the Lincoln cent).
• Any lettering near the rim on a modern coin must not be worn into the rim in order for it to grade "Good."
• Within the grade of "uncirculated," there are different levels of brilliance that can cause one uncirculated coin to be graded higher than another.

For example, an uncirculated coin that has fingerprints, smudges, and nicks may grade only "Mint-State 60," which is the lowest possible grade an unicrculated coin can be graded.

However, an uncirculated coin with absolutely no nicks, dings, smudges, or spots whatsoever technically is considered perfect (or, as the coin grading scale would say, "Mint-State 70" - the highest possible grade for a coin).

The 2009 Lincoln Bicentennial One-Cent Proof Set brings collectors all 4 special reverse (tail's side) designs which have been included on 2009 Lincoln cents.

Before this, the 2009 Lincoln Bicentennial proof cents were shipped in a large proof set offering -- which also included the 2009 nickel, dime, quarters, half-dollar, and dollar coins.

What makes the 2009 Lincoln Bicentennial One-Cent Proof Set distinct is that it includes only the 4 Lincoln cents. This gives collectors who want just those coins a chance to avoid having to pay over $20 more to purchase a bunch of unneeded coins (as would come in the regular 18-coin proof set).

A New Jersey coin dealer has released 107 rare coins into circulation to help promote more interest in coin collecting.

Some of the rare coins include the famous and valuable 1955 Doubled-Die Lincoln cent, worth about $1,000 and up.

In fact, the value of all the coins being released is $4,000!

And don't forget, rare coins travel. So these coins can last in circulation for months and even years before being discovered by someone astute enough to realize they are holding a rare coin.

Even if you are outside New Jersey and it is a year or more after the release of these coins, there is a fair chance that some of these rare coins are still floating around in change near (or even on) you!

In fact, even when there aren't advertised rare coin entries into circulation like this, you should still keep your eyes open for rare coins in your pocket change. Somewhere in this country, several rare coins are likely floating around, just waiting to be found by a lucky collector -- and that lucky collector could be you!

Simple, right?

Well, it is. But coin collectors also need to keep track of the coins they are putting into their collection.

A coin inventory (or coin log) is something that every coin collector needs to have. Keeping track of your coins is important for these reasons:

• Knowing which coins you already have
• Knowing which coins you still need
• Determining the value of your coin collection quickly & easily
• Getting an at-a-glance look at the many coins in your collection
• Documenting your collection for coin insurance purposes

Why? Because PVC can damage coins. The damage to coins contained inside coin holders made with PVC is often irreversible and causes coins to lose much, if not most, of their value.

Why would PVC ever be used anyway? 

PVC was popular in coin holders during the 1970s because the chemical allowed plastic coin holders to be pliable. However, during the early 1980s, the dangers of PVC became known, and production of coin holders containing PVC soon declined. Yet, many of the old PVC coin holders still exist, and you have to be careful to not accidentally place any of your coins within them.

First things first:

• It is generally safe to assume most plastic coin holders made today will not contain PVC. But double check the coin holder's packaging to make sure!
   
• Assume any plastic holder made many years ago probably does contain PVC.
   
• If a coin has severe PVC damage, you will be able to tell because the coin will typically show signs of corrosion. Coins with PVC damage usually look green in some areas.

Whether you just have one old coin or several, someday there will come a time when you want (or need) to find the true value of your coins.

Appraising a coin collection, especially if it contains rare and valuable coins, generally requires you to do a few things:

• Grade your coins
   
• Don't clean your coins - that will lower a coin's value
   
• Slabbing your coins will provide you a chance of getting the same price for them no matter to what dealer you sell
   
• Get an idea as to the value of your coins beforehand so you don't get ripped off
   
• Get more than one appraisal so you have an "average" estimate -- and take the better offer

I cannot overstress the idea of getting a general idea as to the value of your coins before actually getting an appraisal. If you don't know what your coins are worth -- roughly -- then you risk getting an appraisal from an unscrupulous coin dealer who will snag away that $1,000 coin for $50.

Check out a current edition of a coin pricing magazine at your local news stand or bookstore to find out more about your coins' values. Most of these price guides also have a basic guide to grading which will help give you a better idea as to what your coins may be worth.

Chances are you may have actually made one if you've ever visited a tourist hot spot or roadside attraction.

An elongated penny is simply a penny that has been squashed in a machine, producing a design on the coin and making the coin oval shaped and longer than it used to be.

Elongated pennies have been popular since the 1893 Columbian Exposition and, since then, have been made into hundreds of designs.

Elongated coins are fun to collect and, often, don't cost much either to make or buy. There is even a museum dedicated to elongated pennies.

It is common for an elongated penny to cost no more than $1 to make in person. Many older elongated pennies can be bought for less than $5 or $10 from a enlongated penny dealer.

Elongated pennies typically fall into the realm of coin collecting called exonumia, or novelty coin collecting.

Many readers are leaving comments about cleaning pennies with vinegar and other things like ketchup, pencil erasers, and baking soda.

While those things may make coins (especially pennies) look bright and new, you should know that cleaning your coins will actually harm them.

How can cleaning pennies with something as common as vinegar, erasers, and baking soda hurt them?

It's really quite simple...

• Pennies: 50 coins (50 cents)
• Nickels: 40 coins ($2)
• Dimes: 50 coins ($5)
• Quarters: 40 coins ($10)

Not too hard, huh? It really is not. Remembering these numbers is easy after you make or break a few rolls yourself and get a feel for each.

Looking through rolls of coins is also a great way to find old, rare, and silver coins, too. So be sure to peel apart a few rolls from the bank to see what you can find inside!

The penny pyramid in the video contains over 289,000 pennies (1 ton of pennies) and can potentially grow to a whopping 500,000 pennies!

The penny pyramid is being built for a good cause. Mr. Carlos Conde is among the 50,000 who died in 2006 of colorectal cancer, and the penny pyramid is devoted to bringing awareness to getting colorectal cancer screenings -- which everybody should have done by age 50 (if not before, based on family history and other factors).

By the way, I have to wonder if any of those hundreds of thousands of pennies just happen to be among the several rare or scarce Lincoln cents which collectors and investors love. Hmm... imagine how long it would take to check all those pennies!

That's right, I'm talking about coin magic and coin tricks.

Coin tricks are really simple. In fact, coin tricks are among the first types of magic tricks most illusionists attempt to do (you know, before going into all that people-levitating stuff!). 

Of course, behind every illusion are the ingredients which make the "magic" happen.

Coin tricks typically involve:

• Two-headed coins (otherwise lumped into the category of novelty coins)
   
• Coins with the "wrong" faces (like a Roosevelt dime design on the back of a Lincoln one-cent coin)
   
• Several regular coins -- which the audience may not see all at once
   
• Foreign coins -- used to make United States coins "turn into" foreign money

Each trick, of course, has it own set of requirements, so you may not need all the coins listed above to get started with your coin magic tricks. This list should, however, give you some idea as to the types of things coin illusionists typically need to make their coin magic tricks successful -- and magical!