A rumor that the new Apple iPhone -- commonly called the iPhone 5 -- will cost $800 upon its release shocked Apple fans when it hit Twitter early Thursday morning.

Rumors about the Apple iPhone 5 emerge every single day, but almost none of them ever trend internationally on the popular social networking Website.

But at one point early Thursday the phrase "iPhone 5 $800" was the second-most-popular non-promoted trending topic worldwide, and the third-most-popular non-promoted topic in the United States on Twitter.

According to the social trend tracking website Topsy.com, 4,007 people mentioned the phrase "iPhone 5 $800" on Twitter between 3:00 a.m. and 4 a.m.

The surge of focus on the iPhone 5 came as scores of people responded to the rumored price tag, which was almost universally considered far too high for a mere cellphone (even if it turns out be a groundbreaking super-smartphone, as many Apple fanatics hope it will.)

For instance, Twitter user @Danny_Ventura_ tweeted the following: "iPhone 5 $800? It better be waterproof, fireproof, crackproof, dirtproof, bulletproof also."

And many Twitter users made humorous remarks about the amenities that the Apple iPhone 5 should come with if the company wants people to shell out $800 for a cellphone:

"iPhone 5 $800 ??? Better be able to touch their face when we FaceTime," tweeted Twitter user @ODonLannie_ Thursday morning.

But despite all the attention being lavished by social media users on the rumored $800 iPhone 5 price tag, it was unclear as of early Thursday where exactly the new rumor had sprung from, and what exactly made it so popular, while so many other Apple iPhone 5 rumors make hardly a dent on Twitter.

Only three references to the Apple iPhone 5 and a possible price tag of $800 appear to have emerged in recent days, according to a simple Thursday morning search on Google News.

The first is an article on the website gamenguide.com, which includes a purported screenshot of a listing on the Chinese auction site taobao.com that depicts a photograph of what is said to be the iPhone 5, next to a price tag of $5,088 to $6,688, which the article says is the Chinese equivalent of 800 to 1,050 United States dollars.

Though not much more explanation is offered, it is clear that the suggested implication readers are to draw is that the Apple iPhone 5 will cost between $800 to $1,050 upon its American release date. Then the article mentions a taobao.com seller hoping to get people to pay $1,100 for an iPhone. But the article does go on to clarify, adding that the situation is probably an elaborate scam aimed at ripping off unwitting American Apple lovers:

"Obviously, the iPhone will cost a pretty penny, but pigs will fly before it costs that much. Some sellers are even asking for a deposit, despite that they can't give a delivery time for the product," the article states. "Hopefully, not many will fall victim to potential scammers, and that seems to be the case for the time being."

If this gamenguide.com article is the impetus for the $800 iPhone price tag rumors, then it appears that whoever spread it via the social-networking site didn't read far enough to understand why that number was attached to the phone.

But a second, more reliable source has also mentioned the iPhone 5 and the number $800 in the same breath in recent weeks, namely Reuters.

On Wednesday, the international newswire published an in-depth analysis of the prospects for Apple stock in coming months, particularly as the Apple iPhone 5 release date -- which has not been officially announced yet but has been rumored to be as soon as sometime in the next eight weeks -- nears.

The only sentence in that article that mentioned that $800 figure was about the fact that many ratings agencies and other firms are downgrading their outlooks for the stock, suggesting that the iPhone 5's release will not have as much of a positive impact as the iPhone 4 and 4s, iPad 2 and the "new iPad" -- aka iPad 3" -- and other Apple products' releases have had on the firms stock price per share. Here's that excerpt:

"J.P. Morgan Securities cut its price target on the stock to $675 from $695, Raymond James slashed it to $730 from $800, and Canaccord Genuity reduced its target slightly to $797. Goldman cut its price target to $790 from $850."

Beyond that, the article doesn't mention the number. In other words, it's not smart to put too much stock in the information contained within it.

But there is one more source that has put $800 and iPhone 5 in the same vicinity as one another in recent weeks, but it's one with even less credibility than the first two: it comes from a commenter on a phonesreview.co.uk article printed on July 20. The commenter, one Trejo495, tells a fellow commenter what he believes the iPhone 5's price tag will be when it hits shelves:

"Propably [sic] $800-$900 US dollars for 64GB. That's excluding taxes."

But in the end, the "Apple iPhone $800" rumor appears to be just that, another rumor sweeping across Twitter. So take it for what it's worth.