Okay so my bf and I saw a penny that looked odd and started getting into coin collecting a few day ago, but are newbies! We found a 1974 penny and the D below the date is filled in. Every other penny we've looked at, the D has the normal whole or whatnot in the middle. Would something like this make it rare, or a common mistake? Can't seem to find it via google and thought maybe someone could help! Thanks :)
It's technically a mistake or 'error', but it's a very, very minor one. It's called a 'filled die'. This happens when either a die has become worn, or clogged with grease, dirt or dust, in the affected area. It adds only a small amount of increased value. If it was brilliant red uncirculated, you might get $3 - $4. A circulated coin, a lot less. There are people who try to get a couple dollars each on eBay and they fail. Coins from 1974 aren't old. They're considered modern and plenty are still in circulation.
that's common , its just a small error in the stamping process and millions of pennies of all years have it plus its an old penny so even if it was perfect years of use can rub it off or make it smooth the only 1970s penny with any value was a 1772 penny that had been double struck but there were only a few hundred that got out I have a few dozen rare coins and pennies are rarely valuable , even the so called valuable ones are worth $5 or so ( a big jump from 1 cent but hardly worth collecting )