Rich Cache of Amber Full of Prehistoric Creatures Mined in Caribbean : Dominican Republic: The fossilized tree resin has been used as decoration since the Stone Age.

High in the hills surrounding this city in the Cibao Valley, hundreds of narrow openings tunnel into the world’s second-richest cache of amber.

For scientists, the ancient tree resin found in the tunnels brings a glimpse into primeval life in the West Indies through perfectly preserved prehistoric creatures.

For mine owners like Ramon Martinez, the tunnels mean annual sales of about $25,000 in a country where the per-capita income is less than $500 a year.

For amber miners and their families, the tunnels mean three meals a day and perpetuation of a family occupation.

Gem-like in its rich shades of gold, orange, brown and, rarely, blue, the fossilized tree sap has been used as a decoration and good-luck charm since the Stone Age.

The largest and most accessible source is the Baltic coast, where resin is easily mined in shoreline deposits and sometimes even washes up on beaches. Amber is also mined in southeastern Mexico, Canada, China, the Middle East, Alaska, Australia and New Zealand.

But it is in the dense subtropical hills of this poor Caribbean country that some of the most valuable amber samples--those containing the prehistoric insects--are found.

Millions of years ago, trees from now-vanished forests produced a sticky resin that slowly hardened into iridescent clumps. Often the hardening sap became a premature tomb for an unlucky grasshopper or tick.

Today, a piece of amber with such contents is worth thousands of dollars. A rock with a 30-million-year-old lizard trapped inside is worth about $15,000, Martinez said.

Not long ago, Dominican miners tossed out such pieces, believing them to be flawed and worthless. Now, proceeds from such a find can feed a miner’s family for months.

Martinez employs five teams of seven or eight men to extract amber from his mines. Dominican miners earn about $10 a day, according to some industry sources--twice the average salary of their counterparts in the sugar cane and coffee fields, the country’s main sources of income.

“They live simply, but they’re not destitute,” said Patrick Fagg, a jeweler who sells amber in the northern resort town of Sosua.

Most miners live near the tunnels in the Cordillera Septentional mountain range in huts made of tin or palm leaves. They spend their days about 600 feet underground, where they crouch or lie in the light of flickering candles, chipping the amber out of hard rock.

Despite long hours and high risks, most amber miners wouldn’t consider leaving the trade into which they were born, says George O. Poinar Jr., a paleobiologist at UC Berkeley and author of several books on amber.

About 500 families work in the amber mines of the north-central Cibao Valley, Martinez said. The miners’ age range, he says, is 10 to 60.

Martinez, 42, has worked in the amber business for 30 years. As a teen-ager, he and his brothers followed his uncle to Santiago’s mines to buy small pieces of amber. It was about the time the Dominican government began to see amber’s potential as a mineral export.

In his tiny shop in a large, run-down market on the outskirts of town, Martinez shaves and polishes the crude amber brought in daily from his mines. He sells it to buyers from Japan, Italy and the United States.

Three years ago, he provided American movie producers with a piece of amber containing an ancient mosquito. It inspired an incident in the 1993 movie “Jurassic Park.” In the film, scientists use dinosaur blood inside the mosquito to reconstruct and clone dinosaurs.

Dominican amber sales jumped fivefold in the aftermath of the science-fiction hit, Martinez said. The movie also spawned a thriving counterfeit amber industry. Street vendors around the world sell unwitting tourists realistic plastic pieces that sometimes contain newly dead frogs or lizards.

“There are some spectacular forgeries out there,” said David Grimaldi, an entomologist at the American Museum of Natural History in New York.

One way to tell the difference: True amber, when rubbed hard, emits a pleasant pine scent. It also becomes electrically charged.

Although demand for the semiprecious material has fallen in the last year, scientists still consider Dominican amber unparalleled for its fossils.

“The preservation is unreal,” said Francis Hueber, a paleobotanist at the Smithsonian Institution in Washington. “We’re able to dissect the amber and expose the actual structures of an (prehistoric) insect’s muscles, eyes, jaws and nervous system.”

Miners say amber is less plentiful now than it was a decade ago, but few in the industry believe that the world’s supply will be depleted anytime soon.

“Deposits are always being discovered,” said Grimaldi. He and a team from the American Museum recently found several significant 90-million-year-old deposits near Raritan Bay, N.J.

Amber is removed with high-tech mining and dredging equipment in most places. In the Dominican Republic, the miners’ only tools are hammers, chisels and calloused hands.