These are nice gold coins from the old French Republic:
10 FRANCS: 0.0933 troy ounces gold
20 FRANCS: 0.1867 troy ounces gold
Their value is a combination of gold content and coin collector premium.
To compute the base value (BV) of your coin, multiply its gold content by the current prince of gold. For instance, a 10 franc coin has 0.0933 troy ounces and, say, gold is trading at $1500 US dollars per troy ounce, the BV = 0.0933 x 1500 = $140. The price of gold changes every day, so be sure to look it up on web sites such as kitco.com.
Britain ruled India until 1947. The East India Company issued many interesting coins and did not stick religiously to standard circular shape. Most of the British East India coins show the reigning British monarch on the front with rupee, mohur, and anna denominations on the back. The square pattern in our picture was used on the 1/2 and 2 anna denominations during the mid 20th century. You can see an example of a wavy-edge 1 anna coin at this CoinQuest link.
This coin from Czechoslovakia is made of copper-nickel. Since it is a modern coin made of non-precious metal, it is worth very little. Circulated coins are worth less than $1 US dollar. A fully uncirculated coin may sell to a collector for $1 or so.
Starting in 1983 the UK standardized the 1 pound coin as shown in our pictures. The bust of Queen Elizabeth changes after 1983, and the reverse side changes from time to time. All the coins you find in circulation are made of nickel-brass and are worth face value: one pound in the UK. You can use xe.com to figure exchange rates between currencies of various countries.
In addition to the business strike coins produced for circulation, the Royal Mint also produced proof coins for collectors. You can see the sharp difference between the proofs and business strikes by considering our secondary picture. Four the the coins are proofs; one is a business strike. It doesn't take a rocket scientist to see the difference!
Tunisia is a small country with a checkered past. Located accross the Mediterranean from Italy, on the north coast of Africa, it was part of the Ottoman (Turkish) Empire. But forays into high seas piracy was its downfall. Tunisia was taken over by the French in the late 1800s and remained so controlled until 1956.
The 10 and 20 franc coins addressed on this page are made of gold. There are also silver versions of these coins, which came later, after 1928.
Hi Deb -- You probably have a well-worn 8 reales coin from the old Republic of Mexico.
These coins contain 0.786 troy ounces of silver. So that sets the minimum value they can attain. For instance, if silver is selling at $12 per troy ounce (look it up for today's price at kitco.com), the minimum price is 0.786 x 12 = $9.40.
Coins with the liberty cap and starburst pattern were minted in smaller denominations than 8 reales. In fact, denominations of 1/2, 1, 2, and 4 reales look the same, only smaller. The denomination appears explicitly on the coin in the place where '8R' appears on the 8 reales. Look for '1/2R', '1R', '2R', or '4R' on your coin and, if you have one, click to this appraisal page.