SAN ANTONIO -- To the untrained eye, it looks like an unusual rock. Thankfully, the team of archaeologists digging near the Alamo knew better.

That "rock" is the tip of a sword likely used by an uncommissioned officer in the Mexican Army before or during the Battle of the Alamo.

"San Antonio's got a really rich archeological record, but we're pretty excited. We didn't expect it," said archeologist Nesta Anderson who led a Thursday morning press conference about the discovery.

The team has two hypotheses about how the sword tip broke off: It could've broken while a Mexican soldier used the sword as a construction tool during fortification before the battle. Or, the break might have been related the battle itself.

"That is one of the possibilities, which is pretty exciting to think about," Anderson said.

The rock-like appearance of the sword tip is the result of years of exposure to the elements.

"The air, the moisture, everything around us causes the chemical reactions to corrode metal artifacts," Anderson said.

The artifact will now head to the Center for Archeological Research at the University of Texas at San Antonio to be prepared for curation.

"We're pretty excited," said Anderson. "It's pretty rare."

Finding out who the sword belonged too is going to be tough, if not impossible. Unless, that is, someone finds a letter from a Mexican soldier complaining about breaking his sword in 1836.

"Absolutely," said Anderson. "If anybody's got that out there, we'd love to take a look."