Hi Deb -- You probably have a 8 reales coin from the old Republic of Mexico. They are fascinating collectible coins. Be sure your coin is genuine. Check our discussion of fakes below.
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 $18.25 per troy ounce (look it up for today's price at kitcosilver.com), the minimum price is 0.786 x 18.25 = $14.34.
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.
There is an elaborate system of mints and mint marks for these coins. Identifying each element of the mint system is beyond the score of this CoinQuest forum. If you are interested, get a good coin catalog which brings all the details to light.
The general progression of catalog values for most dates of the 8 reales goes like this:
8 REALES BEFORE 1857
worn: $25 US dollars approximate catalog value
average circulated: $50
well preserved: $100
fully uncirculated: $200
8 REALES AFTER 1856
worn: $20 US dollars approximate catalog value
average circulated: $28
well preserved: $36
fully uncirculated: $110
but, these old 8 reales from Mexico have a long history. The further back you go, the more valuable they get. There are several variations of this coin and some of them can be quite valuable, cataloging for hundreds of US dollars even in worn condition. Coins worth $150 or more in worn condition are shown in the list below. Some of these are quite valuable, tipping the scales over $1000 when in uncirculated condition. Worn coins do not reach this high. Check your coin against this list. If you have one of these, investigate further -- it's a good one!
*BETTER DATES* - following values are for coins in average circulated condition:
1823 Mo JM: $300 average circulated
1824 Mo: $135
1824 Do RL: $500
1824 Mo JM with 'REPULICA' instead of 'REPUBLICA': $9000
1824 Go JM: $400
1825 Go JJ: $925
1828 Mo: $70
1831 Ca MR: $1750
1832 Ca MR: $200
1833 Ca MR, 1834 Ca MR and 1834 Ca AM: $550
1833 Mo: $650
1835 Ca AM and 1836 Ca AM: $225
1836 Mo MF: $65
1836 Mo ML: $110
1837 Mo: $75
1837 Ca AM: $1150
1838 Ca AM: $200
1839 Ca RG: $1250
1840 Ca RG: $500
1841 Ca RG: $110
1843, 46, 47, 48, 49 and 50 Ca RG: $75
1847 Mo MF: $3000
1851, 52 and 53 Ca RG: $210
1856 Ca RG: $575
1857 Ca JC: $100
1858 Ca BA: $3500
1858 Ca JC and 1859 Ca JC: $85
1865 Ca FP: $2150
1865 Ca JC: $210
1866 Ca FP: $2000
1866 Ca JC: $1150
1866 Ca JG: $1600
1867 Ca JG and 1868 Ca JG: $175
1868 Ca MM: $125
1877 Ca AV: $210
1880 Ca AV: $350
1880 Ca PM: $800
(There may be more valuable dates out there: trying to list them all here is exhausting. If you have a coin with good eye appeal that is not listed here, pursue it further. If you have one in our list, seek out a knowledgeable collector or coin dealer for an in-person appraisal.)
Here is close-up of a nice specimen: