THESE are bittersweet times for the art of oriental rug-making as practiced in Iran. Persian carpet prices have rocketed to astronomical heights - five to ten times higher than they were in 1960. The finest examples of the art are just about the only furnishings available to a Washington area house that could appreciate even faster than the house itself.

These days, the better handmade carpets from Iran are increasing in value yearly from five per cent for the lesser quality weaves to more than twenty per cent for antiques and semi-antiques in top condition, with the median being from ten to fifteen per cent annuallY.

But the poignant reason for this price rise is that the finest flower of the ancient Persian art is in its final season. The continued industrialization of Iran is seeing to that. Authorities estimate that by 1990 production of the most exquisite carpets will be reduced to a scale of availability equivalent ot that of the Aubusson carpets of France, the last of a centuries-long reign of carpet-making for the courts of French royalty.

The dwindling supply of Persian rugs is felt especially keenly in Washington, for this area - because of its high incomes - is one of the world's major markets for oriental rugs. Treasure-Making

Up to a point, all rugs are made in the same manner: A loom is set up and bracketed to determine the size and shape of the rug. One set of backing threads, called warps, are strung to the length of the finished carpet. A second set, called wefts, are strung across and interlaced with the warps.

The pile material - wool, silk, rayon, nylon - then is woven through the warps and wefts.

In a standard carpet, this pile material is merely looped through in a continual series of V's or sine wave patterns. The carpet strength, such as it is , is at the top of the V's. In time, as continual walking wears on these V's, the strength is scuffed away.

In a Persian carpet, however, this pile material is not just woven through, but tied down in a series of running, interlaced knots. Thus the carpet's strength is not merely at the top of each tuft of pile, but down at the backing level as well. Result: a carpet that may last hundreds of years though it receives daily, arduous wear.

It is the tying process that makes the rug so expensive. Any work of art takes time to create; it takes an extraordinary length of time to make a Persian carpet.

The knot-tying may be repeated twenty-times or more in the length of a running inch. In a single square inch there may be 100, 200, 400 - as many be 700 - individually bound knots. An average-size rug may have the same knot repeated two million times more, a process that may take from three of five people more than a year to complete.

In addition, the carpet-making process is primitive even by Williamsburg standards. Even on pre-Industrial Revolution rug looms, the pile material is beaten against the warp of weft threads by machine - hand or foot-operated but a machine nonetheless. In Iran, however, this is done by hand-held weft beaters that may have at best a dozen blades. For tighter knotting, the beaters are driven down into the pile with hammers. In this manner, a tightness of pile packing is achieved that could be duplicated only in normal commercial operation through use of extreme power assistance.

Iranian carpets, like fine French wines, are named after their cities of origin. Today, the very finest carpets - those with the tightest knots, the best materials, the most intricate and colorful of designs - come from Tabriz, Qum and the Isfahan-Kashan-Nain triangle.

In the very best of these carpets, you can force you fingers into the pile barely a quarter reach the bottom warp. There are the ones that come at least 400 knots to the inch; their colors and designs shimmer no matter what the lights or the viewing angle.

Also liable to cause shimmers are the prices. While many good carpets sell in the $25-to $50-per-square-foot range, a fine Nain casually retails for $200 and up per square foot. That's per square foot! Add silk, add age, and a three-by-five carpet can easily cost $3000. The mind boggles.

The mind should boggle. More to the point, anyone about to plunk down three biggies for a bathmat should be an absoulte font of expertise in the art and mechanics and history of the Persian carpet.

Surprisingly, few people are. Perhaps nothing points up this seeming slip more than the fact that one of the most popular Persian carpets in this country - the so-called American Kerman - is virtually unknown in its native land.

Featuring a large, open field around a central medallion, this carpet is made exclusively for the American market. It is not favored by purists, is not a "rugman's rug," as the saying goes.

The American Kerman has an unusually long, deep and fine pile, the wool coming from the soft underbelly of the sheep.For this reason it does not last nearly as long as the three-century storied lifetimes of the closer-cropped, more tightly-knotted examples of the genre.

The Meaning of it All

As there are hundreds of separate designs indigenous to Persian rugs, so are there a like number of stories that may be spun, like 1001 Nights, about the history and mystery of it all. And as with history, some of it all. And as with history, some of it is a apocryphal - all the more so in this case because no one, not even scholars, can cite true history and design meanings.

Take, for example, but one motif, the popular Boteh design, basically an egg with a tail attached, native to the Saraband region of the Sarouk weaves and now found copied all over Asia.

In Persian, Boteh literally means a cluster of leaves. But today explanations of the exact meaning are legion, the design being called variously a pear, cypress tree, pine cone, leaf, likened to the Sacred Flame of Zoroaster, the bend of the River Jumna as it leaves the Vale of Kashmir, a teardrop and a clenched fist making a seal in blood.

What it comes down to is pick the story you like, then entertain your friends. You could be right. One thing is sure: no one will seriously dispute you - unless their tale is even better. If You Buy . . .

In the end, perhaps the best way for the novice to learn about these carpets is the hardest: read and study.

There are a few books on the subject, though not nearly as many as for-say. American antiques. Some of the coffee table display variety can be insufferable snobbish, decrying anything less than a 100-year-old vegetable-dyed palace Kerman as not worthy of attention.

Perhaps the most acacemic work on the subject, for Americans, is Murray L. Eiland's Oriental Rugs, though its dense and technical prose is hard going for the uninitiated.

Far more accessible to the ordinary reader is Charles Jacobsen's Oriental Rugs. He goes into great detail on how the novice can avoid getting his pockets picked by shyter dealers or their fiscal fingers burnt by itinerant auctioneers.

Beyond that, legwork - going from shop to shop and back to the books - is the surest way of (eventually) obtaining a sound investment. The first visit to the shops is almost certain to be confusion supreme. In the oriental rug business, just for openers, dealers cannot even agree on how to spell the names of the darn things.

For example we have: Isfahan, Isphahan, Isphehan, Isfehan. Or maybe you prefer: Saruk Sarouk. And there's always: Kerman, Kirman, Kerminh, Kermann, Kirmanh. Or why not try: Bokhara, Bukhara, Bokara, Bukara (or, more properly, Turkoman). And the winner and all-time champion: Goum, Ghoume, Gouhm, Quum, Quhm, Kum, Kuhm.

Oriental rug purveyors may be found in individual shops and as franchises of major stors, with the concentration dotting both sides of Wisconsin Avenue from Georgetown through Bethesda.

Others seem mere storefront operations (and they are), heaped with rugs and the dust of their travels. Swarthy attendants lounge against the walls with set grimaces upon their faces, looking for all the world like leftover extras from some vague Palestinian war. On beckon from the salesman, they sling room-size rugs into the open, raising great clouds of dust. In such establishments, intimidation seems the sales key.

At a select few, elegance and dutiful attention to the buyer is the approach. Soft quiet prevails; suits are worn by all. Chairs are offered, demitasses of coffee proffered.

At W&J Sloane's Bethesda store on one somnolent weekday afternoon, a matron of uncertain years but of definite bearing whispers a request to be shown some hall runners. A silent nod, and an attendant appears bearing rolled carpet to about fifteem feet from the good woman. The carpet is dropped softly to the floor: no dust is raised. A kick of a smartly shined loafer sends the carpet rolling forward. A few more gentle nudges and it is all unrolled, the cotton fringes at the end barely kissing m'lady's feet. Perfect gauging. The lady smiles in appreciation, as much for the way the carpet is presented as for the good itself.

One popular way to acquire a Persian carpet is at auction. These can be entertaining, informative and amusing. And as with anything else so adventurous, there lies danger as well.

Buying through estate auctions is one thing: but books, buyers' guides and dealers all warn against itinerant auctioneers - and of these, Washington is fraught with more than its share. TThree for the Road

This account now concludes with an introduction to three area dealers worthy of the reader's particular attention.

They are James Keshishian, who runs the Bethesda store begun by his father, Mark, a half-century ago; Charles Coe, curator-in-residence at Sloane's in Bethesda; and Donal Overheu, an iconoclastic naverick who operates out of Northern Virginia - but who particularly may sometimes be seen lugging thousands of dollars worth of rugs to and from our more famous local law firms.

Keshishian, more than any other dealer, takes the culture-cum-education approach to selling rugs. Over the years, he has built and entire marketing plan around a continuing series of lectures on the art and mechnics of the Persian carpet.

Coe, working with a prospective customer, is concerned decorating adviser, fitting the carpet to the existing decor.

He and Keshishian agree that the best way for the novice to gain carpet knowledge is through trusting in a reputable dealer, though Keshishian takes the admonition one step further with the slight warning, "Caveat emptor."

One gets the clear feeling that no emptor need caveat in either of these old and fine stores.

Overheu, for his part, goes in quite another direction. Rather than discussing decor, he strikes more at the purity of the art - demanding, even, that the client immerse himself in the knowledge of it all, the better to more fully appreciated the investment.

Overheu, like Coe, is native American with no blood ties to the Middle East. He also worked for Coe for seven years at Sloane's before going on his own as an independent Oriental rug consultant, quite posssible the only person in the country to operated in such a manner.

The three all agree that trafficking in Persian rugs is no place for the novice trader.

"Over the long haul," says Coe, "these carpets will appreciate. But you cannot expect to realize a quick profit any more than you can expect to make a killing in a growth stock overnight."

In a separate conversation Keshishian adds: "Our clients who got into the game early, ten or fifteen or twenty years ago, now they're starting to realize a fine return on their original investment.

"But the people who get something and try to make a quick killing? Forget it."

So where does that leaves the interested person who wants to buy, or the collector who wishes to sell?

Overheu leans forward. "Look, these things aren't the Secrets of the Ancients.It's all there. In books, in museums. Read, learn. Then go out and shop and compare. Get everyone's opinion, then go out again."

The inevitable question is posed:

Who is to say that, 100 years from now, when all of us are long dead - and the making of fine Iranian rugs is also dead - that Indian carpets will be purveyed as genuine, 100 percent Iranian carpets?

Overheu takes a slight sip of wine ans smiles with a slight tinge of cynicism.

"Who says we have to wait 100 years. It's going on now."