Sometimes these replica coins are plated with gold, which makes them look quite spiffy. But, alas, they are still fakes (replica, reproduction, and copy are polite words) and worth about zero.
Genuine coins are absolutely beautiful and worth a ton of money. You can see our page on Kellogg and Company gold pieces at this link.
Side-by-side comparisons of real and fake coins are often useful. The image below shows small deviations between the patterns, although the deviations are quite pronounced upon close inspection. Sometimes counterfeit coins are so accurate and precise only a professional authenticator armed with microscopes and other sophisticated devices can tell the difference. In the United States it is illegal to own counterfeit coins unless they are stamped with the word COPY. Variations of this replica coin sometimes have COPY or a small encircled C or R.
If you are thinking about investing substantial money in rare coins, be sure to deal only with reputable sources.