The frenzied ascent of gold and silver values in the world's commodity markets has continued to spur a dramatic increase in the thefts of precious metals from affluent suburban Washington home owners, police officials said yesterday.

In Fairfax County alone last week, roughly $200,000 in silver and gold, thousand dollars, was stolen in 30 burglaries.

In one case, a wealthy McLean couple returned to their home in the 7800 block of Lewinsville Road to discover the front door of their house had been forced open.

"They were real sick about it," said a police investigator. "Someone had stolen several antique silver sets and coins valued at roughly $78,000, as well as a few fur coats for good measure. They were better off than most. It was all insured."

"They the [burglars] are apparently reading the financial pages of the newspapers," said Fairfax police spokesman Warren R. Carmichael. "The floodgates have opened."

Carmichael added that major silver thefts "of $5,000 and higher are occurring almost on a daily basis" in the county as New York Commodity Exchange values for an ounce of gold ($702 yesterday) and silver ($36.20) have risen sharply from prices of $472.50 and $23.40 recorded Dec. 20.

"It has definitely become a crime of choice," said Fairfax Prosecutor Robert F. Horan.

The increase in precious metal thefts has most seriously affected Fairfax and Arlington County. Although precise Arlington County figures were unavailable, Deputy Chief Len Holsclaw of the major crimes division said an "increase of precious metal thefts by unsophisticated burglars" has been with us for the past several months.

"The burglars apparently realize that a few pieces of metal can be worth as much as a 50-pound television set," Holsclaw said. "And even a plumber could melt the stuff down. Then it is impossible to identify."

Prince William County authorities said they were averaging "no more than one precious metal theft a month" and Fairfax City officials said they have not had a silver theft "since the spring of 1979." Alexandria and Falls Church investigators said there have been no significant increases in silver and gold burglaries.

But in Fairfax County, "to say that we are being inundated" by the '70 reported precious metal thefts since Jam. 3 "is putting it real mild," according to police burglary specialist Sgt. Gerald Crosby.

"The thefts mainly involve silver and largely occur in Groveton along the Fort Hunt Road corridor, and the affluent sections of McLean, Annandale and West Springfield. During one period in late 1979, we were averaging almost $100,000 in stolen metals every three days," Crosby said.

From 1975 to the spring of 1979, precious metal thefts in the area largely were the work of "a small, elite and organized group of criminals who specialized in gold, silver and jewelry," according to Crosby.

"Now you have common neighborhood thieves ripping off everything from antiques to sterling silver candlesticks, jewelry, flatware . . . all the way down to high school class rings," Crosby said.

There have been 20 arrests of precious metal burglars in Fairfax County since December, Crosby said.

Attempts to recover the stolen goods have been hampered by the fact that local investors seldom keep precise descriptions or photographs of the gold and silver they own.

"So many times we'll have a victim trying to describe a stolen article off the top of his head and it just doesn't work," Crosby said. Crosby also said the number of precious metal "fences," the buyers of stolen property, has increased the conduits by which the precious metals are routed out of the county.

The most recent case involving an elleged fence for stolen silver involves the owners of the Richmond Highway Coin and Stamp Center. In a Fairfax County case that was sent to the grand jury last week, Center owners robert McIntyre and Eugene Hall were accused in court testimony of being "one of several conduits for selling precious metals stolen from area homes."

Randall Harvey Riddle, a sell-professed 27-year-old Fairfax County burglar, testified last week that he sold silver "from at least nine county burglaries" to Hall and McIntyre, and was paid approximately $3,500 for the stolen goods.

Holsclaw suggested that majority of the area's stolen silver remains in Northern Virginia.

"Once it goes past the first fencing operation," Holsclaw said, "it becomes high-dollar, white-collar crime. They have to sell it where the money is, to high-class clientele and suburban Washington fits that requirement."