The market runs on the Tor network, so it has no clearnet address of its own. The clearnet pages that exist for it are directories, and some of them are honest, and some of them are the product. This is how to tell the difference, and the rule that keeps you out of the bad ones.
Why clearnet pages exist
A search engine cannot index a .onion site, because it cannot reach the Tor network. So the addresses have to be published somewhere the search engine can see, and that somewhere is a clearnet page. The honest ones publish the current addresses, keep them updated, and say plainly that they are a directory, not the market. The clones publish an address, and the address is the point.
How to recognize a clone
The clone has a title that promises the working link, a recent date, and an address that is close to the real one but not the same. It looks like every other directory, because it is a copy of the format. The tell is the address itself, compared against a source you trust. A directory that is honest about being a directory, that says it is not the market, and that points you to Tor Browser, is doing the job. A page that makes you feel like you are about to enter the market, from a normal browser, is doing a different job.
The other tell is the pressure. A clone that tells you the old address is "dead" and this one is the "only working link" is creating urgency, because urgency is what stops the check. The honest directory does not need urgency. The list is there, the date is there, and the check takes five seconds.
The rule
Compare the address before you use it, against a source you trust, and do not let the page you are on be the source you trust. The source of trust is the market's own signed announcement, or a directory you have used before and that has a history of being right. A page you have just landed on, from a search, is not a source of trust. It is a claim, and the claim is checked, not believed.
The mirror list is the current addresses, and the verification guide covers the signed announcement, which is the deepest check.