I have a republic of Liberia coin as well, and the certificate that came with it states it is copper-nickel.
No silver. They are copper-nickel
If it's silver, then at least $30.00
In 1993 the Republic of Liberia issued a Nolan Ryan 10 dollar silver proof coin. The value of this coin is about $15.
The only silver-colored coins minted by Liberia in 1996 were composed of Copper-Nickel (there were also two gold coins produced in that denomination in that year).
The book value is about 8 to 10 dollars in the Krause Standard Catalog of World Coins. The ten dollar version of the same coin has one once of silver so has the real value.
The James Madison Presidential dollar is made of brass, not silver, and is worth one dollar.
There is no information because the presidential dollar series is being struck in the same copper-manganese alloy as the Sacajawea dollar coins. None are in sterling silver.
The current year Presidential Silver Dollar Proof Sets sell for between $75 and $100 on Ebay. They can also be had at local collectible shops.
No silver or gold in any presidential dollar coins
It is 1 troy oz of 999 fine silver. So its value is the current silver price for 1 troy oz. Depending on its condition there could be some additional numismatic value to collectors too. Current silver price as of this moment is $34.28 per troy oz of fine silver.
President Eisenhower was featured on the large one dollar coin in the 1970s, a commemorative silver dollar in 1990, and a small golden presidential dollar in 2015.
Liberia has produced at least 100 different Twenty Dollar coins since 1983 (mostly from about 1997 onward). The silver content varies by the issue, but the most seem to be either about 2/3 of a troy ounce or about 1 troy ounce.