On the surface, it is just one of the many picturesque villages of Transylvania, a region called Romania's "national treasure" by Britain's Prince Charles for its stunning nature.

But Rosia Montana, a former Roman site in the northwest, lies on one of the biggest gold deposits in Europe: a blessing for some, a malediction for others.

With the precious metal regaining ground as an investors' haven, a Canadian company is pushing to open a mine that has divided locals and triggered a fierce controversy on environment and heritage concerns.

Tens of thousands of tons of cyanide will be needed to extract 300 tons of the previous metal -- a scale unseen in Europe where only one percent of the world's gold is produced.

Recently, Romania's President Traian Basescu expressed strong support for what he sees as a boost for the economy. One of his advisors immediately resigned calling the mine "damaging". The country's Prime Minister Emil Boc has admitted he was "not a fan" of the project.

The Rosia Montana Gold Corporation (RMGC), 80 percent held by Canadian firm Gabriel Resources, acquired a mining license from the Romanian government in 1999.

Since then, it has been awaiting a government-issue environmental permit, facing vehement opposition from green lobby groups, archaeologists, historians, Romania's Union of Architects and the Romanian Academy, one of the country's highest scientific bodies, as well as anti-corruption groups.

Neighbouring Hungary has also voiced concern over the use of cyanide, a toxic substance that caused major pollution of the Danube river after a spill in a Romanian gold mine in Baia Mare in 2000.

Cyanide is commonly used to leach gold from ore. In most European deposits, gold is bound with other metals, requiring such a separation method.

In Rosia Montana, RMGC expects it will use an average 12,000 tons of cyanide a year, according to an assessment sent to the ministry of environment in 2007 and still valid today, the company said.

This is 12 times the amount used in gold mining in the whole of Europe, according to industry group Euromines.

But RMGC brushes away concerns, underlining it will follow the strict requirements of the International Cyanide Management Code.

"The concentration of cyanide in the tailings (residue) pond will be far below the European requirements", RMGC's vice-president for Environment, Horea Avram, told AFP.

Tons of tailings, containing cyanide and heavy metals, will end up in a 300-hectare pond in a nearby valley in 16 years of gold extraction.

A 180-metre high dam that "can resist powerful earthquakes will protect the region from any spill", Avram said, adding the company would rehabilitate the area once extraction ceases.

But Ionel Haiduc, a chemist and chairman of the Romanian Academy, said the "tailings pond is a potential ecological bomb".

"The project in its current form is not acceptable. The open-cast goldmine will damage the landscape and the archaeological sites. Moreover, the benefits for the Romanian state are very limited under the current contract", he told AFP.

The four mountains surrounding Rosia Montana will be partly destroyed by explosives, damaging part of one of the most extensive remaining networks of Roman mining galleries in the world.

"Eighty percent of the galleries will be preserved", countered Adrian Gligor, the RMGC vice-president in charge of heritage issues. "We will be able to reconstruct artificially the ones that are affected" -- adding the company is to spend millions of euros on heritage preservation.

A draft law enabling private mining companies to expropriate land is denounced by rights groups as a helping hand to RMGC, which still needs to buy up some land to make the project a reality.

Adopted by the Senate in 2009, it should be submitted to the lower chamber of parliament soon.

While awaiting a permit, RMGC has already stamped its presence on the village, flagging its logo on the 233 houses it has bought as dozens of its workers walk around in green uniforms.

In Rosia Montana, the project has "planted hatred even within families", deplored Arpad Palfi, the priest of the Unitarian Church for 35 years.

Fathers and sons, brothers and sisters have been fighting over offers from the Canadian company to buy their land and homes. About 2,000 people and more than 400 graves need to be moved.

But RMGC underlines its "significant contribution" to the local community with $1.7 billion (1.3 billion euros) in planned investments and a project it says would add $4 billion to Romania's economy.

"They will take everything there is to take in these four mountains and leave us after 16 years with a poor and poisoned zone", said Josephina Vajdea, a 81-year old woman who refused to sell her house and the garden where she grows vegetables.

"I will never leave my farm," vowed farmer Eugen David. "They will have to come with special police commandos to get me out."

But a 46-year-old resident who said she found work at RMGC and spoke on condition of anonymity, said she supported the project "because it will create jobs, while the state has done nothing for us".

RMGC has promised 2,300 jobs during the two-year construction phase, and 800 more during the 16-year extraction period.

Monica Macovei, a former justice minister praised in Europe for her fight against corruption, however, said "the job issue is not relevant compared to the environmental risks".

"A lot of jobs could be created by including the zone in the national heritage. It could be a splendid tourist area".