Expert: Dmitry Livshits - 12/2/2009

Question
I have just inherited a few coins, some US and some foreign.  I am attempting to learn about this money and it's worth.

I have one coin that has a picture of (I think) a king on the front.  It is about the size of a silver dollar, weighing much the same.  The front says; 1806  CAROLUS.IIII.  DEI. GRATIA   The reverse side of the coin shows two pillars with (pictures) in the middle of them deicting Lions and ?Castles?.  Above this is a crown.  The words going around the coin are;REX.M.8R.T.H   .HISPAN.ET IND.
Do you know this coin?  Can you give me some information on it?
Should this coin be kept in any safe way? Is it worth insuring?
Thank you for your kind attention to this request.
Sharyn  

Answer
Hi Sharyn,
You have a Spanish colonial 8 reales or "Piece of eight" or "pillar dollar" as they are called. Your particular one is from the Mexico City mint, which is one of the more common ones. Such coins were used as currency all over the colonial world, including within the United States.
The depiction is of Charles (Carlos) IIII and the Spanish crest with lions and castles.
The best way to store this coin is by putting it in an air tight plastic holder or in a mylar and cardboard 2"x2" coin sleeve. either of these would be available at a coin shop and cost just a few pennies for the mylar sleeve or about a dollar for the plastic holder.
Current market value ranges from $50 for a well used one to $200+ for one in excellent condition. All of these are pretty crudely struck, so grading is quite liberal and well struck examples bring a premium.
Please don't forget to rate this answer.
Thanks for the question! =)