THE SINGLE-ENGINE Cessna climbs swiftly to avoid a cloud patch, then swoops T toward a slash of brown in the dense green jungle. As the plane nears, the slash becomes a narrow strip of dirt lined by corrugated zinc huts and dusty jeeps. Children and dogs scatter to both sides of the strip as the plane touches down and skids to a halt a few yards from a giant gape in the earth.

We have reached Salvacion.

Dirt roads, dirt floors, dirt-dusted people and vehicles--it is hard to believe that this dull-colored patch of a village is the heart of that most sparkling of jungle enterprises--diamond mining.

But within pits similar to the one just beyond the dusty landing strip, 5,000 men working in groups of five or six spend their days up to their waists in mud, using giant hoses to flush out a fortune. These pits pockmark Salvacion and its tiny sister pueblos in central Venezuela's Guaniamo jungle region.

In recent months an increasing number of adventurous tourists have visited the area, anxious to catch a glimpse of a last frontier where hard work and a lot of luck can make any man a rich man. Immersed in tales of streets paved with diamonds and drunken brawls over women and gems, they explore the dusty streets--perhaps with an added swagger.

The diamonds do not surrender easily. They are reached only after months of digging--sometimes to depths of 36 feet--to the telltale layers of carbon-colored pebbles that offer the best hope of a fruitful harvest. Using hoses to loosen the promising muck from the sides of the pits, the miners sift the sludge through hand-held metal sieves, anxiously fingering all that glitters. Small rubies and emeralds are cast aside, dumped into the mud with quartz and other worthless rocks. The diamond miners, with their tattered trousers and mud-spattered hats, are purists.

"Twelve years ago I came here for diamonds and I am still here for diamonds, only diamonds," says Lorenzo Capella, a barrel-bellied, perpetually sweat-covered Spaniard. At 65, Capella still dreams of the day he will find a giant diamond, a gem like the fingernail-size, 58-carat beauty flushed out by a fellow Spaniard several years ago and rumored to have sold for a quarter of a million dollars.

For now, Capella says, he would be content to find enough small diamonds to pay back the 100,000 bolivares ($25,000) he owes his four workers, the woman who cooks for them, and the town merchants who let him--and all the miners--eat their meals and drink their beer on credit.

Scratching the salt-and-pepper stubble of his beard as he inspects a dirt-filled mesh sieve, Capella explains that as official jefe of his small band of prospectors, he must provide food, clothing, communal shelter and medical care. He also must buy gasoline to power the rustic metal machine that pumps river water through the hoses.

For his patronage he is entitled to 65 percent of the price paid by the diamond buyers whose small stalls line Salvacion's main street-cum-airstrip. These mostly Brazilian merchants pay a standard $100 per carat, then sell the gems to others from Caracas or Europe for triple that price.

After taking his cut, Capella divides the remaining money evenly among the workers and cook. But recently, he says, there has been only enough to pay for gasoline and a portion of the food bill. The workers will have to wait.

"How much do I owe you, old woman?" he asks the cook, who doubles as a nurse maid, fetching him from the town bar each night when she senses he has reached the boundary between satiation and stupor.

"Twenty-four thousand bolivares ($6,000)," she says, smiling--almost proudly, her tongue poking through the empty space where her front teeth have rotted away from jungle diseases.

Few of the miners seem in a hurry to pay off their debts, and there appears little anxiety about fruitless days in the mud pits. For Salvacion is not merely the hunt for diamonds and the resultant wealth. It is also a way of life, and many of the miners confess that even if they should find a fortune, they would probably leave the region only long enough to spend it--perhaps in bustling Caracas, a 2 1/2-hour flight north.

For the miners, Guaniamo is a life of mud-filled days in the hot sun and cool evenings drinking beer and playing domino until the 10 p.m. curfew imposed by the National Guard. It is dropping off to sleep alone on a rope hammock in a zinc hut, or paying $50 for a night with one of Salvacion's 40 prostitutes, most of whom have come to the mines in hopes of finding their own diamonds or of receiving them as bonuses from satisfied customers.

Their hair rolled up in pink and green plastic curlers, the women spend the daylight hours swinging in hammocks, chatting in groups under Salvacion's one large mango tree, and chaperoning their children to and from the tiny school on the town's only side street, directly next door to the medical clinic where every Friday the women are inspected for venereal diseases.

"Prostitution is not legal in Venezuela, but there are laws that are mandatory and laws that are not so mandatory," says Miguel Oscar Pujol, Salvacion's doctor.

Once a week, Pujol makes the 90-minute flight to Salvacion from Ciudad Bolivar, the capital of Bolivar State, which encompasses the Guaniamo region. In addition to performing checkups on the town's women, he also hands out quinine tablets to counter the malaria that thrives in the jungle marshes and which in the early days of the mines killed off thousands of men, women and children.

The mood is peaceful, safe, a world away from the Salvacion of 12 years ago when adventurers first came to the region, drawn by rumors that the Panare Indians had seen strange stones glistening in the jungle riverbeds. (The Indians themselves have never taken much of an interest in the diamonds. Living at the northern rim of Guaniamo in thatched huts shaped like onion bulbs, they prefer to live off fish, mangos, bananas and an occasional monkey or turtle.)

Men from throughout Venezuela and across the border in Brazil and Colombia cut their way through the jungle with machetes, using dugout canoes to cross rivers and swamps. Eventually, they hacked out narrow air strips in Salvacion and Milagro. The 1,600-foot runways still can accommodate only the smallest single engine planes. The tiny jungle villages sprang up wherever the miners set down their few provisions and decided to dig. Salvacion and Milagro grew to 2,000 residents apiece, while other sites, such as El Diablo and La Fortuna, have never contained more than six or seven inhabitants.

The towns are connected by one 37-mile dirt road that looks as if it had been bombed. During the dry season, from December to May, the road can be traversed only by rugged four-wheel-drive vehicles, which bounce in and out of the giant craters and chug through the deep mud kept well-watered by jungle streams. Brakes are quickly worn down by the rocks and mud. To stop, a driver simply turns off the engine.

In the rainy season, from June to November, the roads are virtually impassable--although trucks loaded with the weekly beer rations always seem to make it through. Miners needing to get from one end of the jungle to the other usually must enlist the aid of one of the region's bush pilots, who charge $30 for the seven-minute flight between Milagro and Salvacion.

Death used to be a daily event in Guaniamo. When the miners weren't tearing up their towns they were often tearing up each other. Many old-time inhabitants still bear the ugly facial and arm scars of the machete fights over diamonds and women. As fists amd knives flew, the call would go out over the shortwave radio for a doctor to be flown in from Ciudad Bolivar to piece together the victims of too much whiskey and too many words in a place where too many men had too little else to do with their nights.

The bush pilots who once flew in only medics, now transport provisions, diamond buyers and an occasional tourist. After taxiing down Salvacion's narrow airstrip, they park their tiny planes directly in front of the town's one hotel, a ramshackle zinc edifice called The Miss Italia. The pilots, many of whom are ex-miners who found they could make more money in the air than in the earth, must have keen eyesight to spot the slashes of brown airstrip in the jungle.

Usually the landings are successful, but sometimes they are not, as the pieces of crashed planes scattered at varying distances from the landing strips attest. "Don't fly with the pilot they call Tarzan," chuckles a deeply tanned Brazilian miner named Francisco Carolina. His gold front tooth glistens as he speaks to us over a turkey dinner at The Miss Italia.

"This man is called Tarzan," Carolina continues, his tooth glinting, "because three times he has landed in the trees."

Carolina himself seldom leaves Salvacion except to make the 90-minute flight to Ciudad Bolivar to replenish his supply of Sony Betamax tapes. While no television stations reach Guaniamo, there is electricity, and Carolina has made a lucrative side business charging $10 a head to miners who come to his corrugated zinc shack on the outskirts of town to see movies such as "10," "Star Wars" and assorted pornographic favorites. Carolina says his Betamax is his third most valuable possession, surpassed only by his mining machinery and the large metal safe he keeps beside his hammock.

Carolina is not the only successful entrepreneur in Salvacion. A 30-year-old miner known only as The Mute, because a serious mouth disfigurement makes it possible for him to speak only in grunts, walks the town with a Polaroid camera, charging $10 apiece for pictures of miners to be mailed away to loved ones, or for photographs of particularly impressive diamond finds.

And Margarita and Antonio Bolivar, a fiftyish couple with twin blue jean outfits and eyes pinched by smile wrinkles, have made a small fortune running "Representacion," a short-wave radio post. Miners pay upwards of $10 a minute to place calls patched through Ciudad Bolivar to anywhere in the world.

The radio, hooked up to a loud-speaker system, periodically calls out above the sounds of chickens and children the momentous messages of the day: "Juan Bocarro, you have a call from the United States." "Victor Mateo, report to your home immediately, your dinner is ready." "Francisco Carolina invites all of the town of Salvacion to a barbecue and free beer at his home tonight at eight o'clock."

On Sundays, the loudspeaker also summons the town to the noon baseball game against Milagro, played in one of the few clearings spared the picks and hoses of the diamond hunt. And every night at six, miners tiredly sifting through a final sieveful of dirt before heading for their huts are saluted by the many choruses of the Venezuela national anthem, "Gloria al Bravo Pueblo" (Glory to the Fearless People).

Not all independent endeavors have prospered. Ruben Meneses has been unsuccessful with the laundromat he set up on the outskirts of town six months ago. "The women would rather beat their clothes against the rocks and the men don't wash them at all," sighs Meneses, a tall, spotlessly dressed Argentinian, who came to Salvacion two years ago after working as an engineer at a Venezuelan steel plant.

A syndicate of businessmen with connections in influential places has been gaining government support to establish a giant company that would give them control of the major chunk of the diamond region and its $25-million annual output in uncut gems. Such a move would reduce the independent prospectors to employes of the firm. The miners, who, under Venezuelan law, have no property rights in Guaniamo but only the right to mine specific areas at the government's pleasure, have been fighting the takeover with petitions to the Venezuelan Mines Ministry and paid newspaper ads.

While not particularly religious people, the miners are not above enlisting the aid of the dead in furthering their cause. On the rough road between Salvacion and Milagro, a small fence surrounds the grave of a much-respected Mines Ministry inspector, who several years ago was murdered on the spot. The dead inspector has become something of a patron saint to the miners, who frequently come to the grave to pray for favors--the health of a sick child, success in a newly dug diamond pit. They place small slivers of diamonds on the grave mound as a tribute. In recent months many have increased the size of the slivers and the size of their requests.

"We are praying for the survival of our community as it is, as we have made it," says the Brazilian Carolina. He and a delegation from the Guaniamo Defense Committee beseech departing visitors to take that message with them wherever they are bound. Farewells are otherwise matter-of-fact. Anyone who has come to Salvacion, the miners say, will certainly come back. The region's magic lure lies in the simplicity of its premise:

"Salvacion offers all that you are prepared to struggle for," says Carolina, cradling in his arms a newly arrived shipment of Betamax tapes. Then, smiling broadly, his gold tooth glinting, he adds: "Plus, my friends, one movie on the house."