It depends on the value and when they were made. Lower value coins (10, 20, or 50 centavos) are currently made from stainless steel. Peso coins are bi-metallic (stainless steel/aluminum bronze). Circulating 20 and 50 peso coins are bi-metallic with a silver center.
You may consult the related links below for more information.
intrinsic value If a coin had value because of its metal content, you would refer to the "bullion value" or the "melt value" of the coin, as versus the "numismatic value" that a coin which was rare or in exceptional condition would have.
That number indicates the fineness or purity of the metal content. 900 means the coin is 90% of that metal.
silver on the outside/ small gold coin inside
The "0.720" on the coin indicates its silver content, meaning it is 72% silver and 28% other metals, typically copper. The "Ley" refers to the legal standard for precious metal content in coins. "Mo1992" likely denotes the mint mark and the year of minting, with "Mo" representing the Mexican Mint, which produced the coin in 1992. This information collectively signifies the coin's authenticity and value as a collectible or precious metal asset.
Seems to be the metal coin content, of the coin.
The coin is 90% silver & 10% copper.
In numismatics, the term used to describe the value given to a coin because of its metal content is "intrinsic value." This refers to the actual value of the metal in the coin, such as gold or silver, independent of any numismatic premium.
A 1921 Mexican 1 Peso coin contains 0.3856 troy ounces of silver.
Aluminum and Bronze
It's 80% silver and 20% copper.
If it's a copy, it's not worth much of anything. At best, it's worth its metal content.
A slightly more sophisticated version of the Magician's Coin. Will the Mexican coin come out of the half dollar?