A Mexican . archaeologist hunting for a royal tomb in a tunnel . beneath a towering pre-Aztec pyramid has made a discovery that . may have brought him a step closer : liquid mercury . In the bowels of Teotihuacan , a mysterious ancient city that . was once the largest in the Americas , earlier this month Sergio Gomez found 'large quantities ' of the silvery metal in a chamber at . the end of a sacred tunnel sealed for nearly 1,800 years . And because of the potential supernatural significance of liquid mercury in ritual ends , deeper into the complex Gomez hopes to find the elusive last resting place of a king . Scroll down for video . Hope : Mexican archaeologist Sergio Gomez has been excavating a pre-Aztec pyramid in Teotihuacan , Mexico , for six years and came across 'large quantities ' of liquid mercury earlier this month . Underground : Gomez announced on Friday that he found the liquid mercury in a chamber at the end of a tunnel ( pictured ) that had been sealed off for more than 1,800 years . 'It 's something that completely surprised us , ' Gomez said at . the entrance to the tunnel below Teotihuacan 's Pyramid of the . Plumed Serpent , about 30 miles northeast of Mexico City . If Gomez is right , it could help settle a debate over how power was wielded in Teotihuacan , a city boasting massive stone pyramids that was home to as many as 200,000 people and the heart of ancient empire that flourished between 100 and 700 A.D . Some archaeologists believe the toxic element could herald . what would be the first ruler 's tomb ever found in Teotihuacan , . a contemporary of several ancient Maya cities , but so shrouded . in mystery that its inhabitants still have no name . Unsure why the mercury was put there , Gomez says the metal . may have been used to symbolize an underworld river or lake . Though mercury has previously been uncovered in small amounts at a few Maya sites much . further south , it had never been found in Teotihuacan . Mercury was rare in ancient Mexico , as it was difficult to mine and prized for its reflective properties . Archaeologists believe it may . have had a supernatural significance for ritual ends . Teotihuacan , or 'abode of the gods ' in the Aztec language of . Nahuatl , was distinct from the Mayan civilization . Royalty : Gomez said that he is unsure as to why the mercury was in the tunnel ( pictured ) , but he hopes that it will lead him to the tomb of the city 's king . Digging : National Institute of Anthropology and History ( INAH ) archaeologists work at a tunnel that may lead to a royal tombs discovered at the ancient city of Teotihuacan in 2011 . Gomez said their findings could lead to settling the debate as to how power was distributed in the city . Its . inhabitants left behind no written record , abandoning the city . long before the Aztecs came to power in the 14th Century . Spaniards dug at Teotihuacan in the 1670s , but rigorous . scientific excavation of the site did not begin until the 1950s . Gomez 's six-year slog in the tunnel has already yielded tens . of thousands of artifacts including stone sculptures , fine . jewelry and giant seashells leading to the three chambers . The . painstaking excavation has slowed due to extreme humidity , mud , . and now , the need for protective gear to avoid mercury . poisoning . George Cowgill , a U.S. archaeologist who has spent more than . four decades excavating Teotihuacan , says the mercury find . increases the odds of finding a tomb . 'But it 's still very uncertain , and that is what keeps . everybody in suspense , ' he added . Mexican archaeologist Linda Manzanilla believes that at its . peak , the city was ruled not by a single king , but a council of . four lords , and that Gomez may find the remains of one of them . To bolster her argument , she cites the absence of a single . palace or the presence of kings in any of the city 's many . murals . The excavation of the chambers should be finished by . October , Gomez said , with an announcement of findings by the end . of 2015 .
Mexican archaeologist found mercury in chamber of Nahuatl pyramid . The chamber had been sealed at the end of a tunnel for nearly 1,800 years . Because of the potential supernatural significance of liquid mercury in rituals , archaeologist Sergio Gomez hopes to find king 's tomb in pyramid . Nahuatl , or 'abode of the gods ' in the Aztec language of Teotihuacan , was distinct from the Mayan civilization .