Inflation can be insidious, eroding our net worth with the stealth and inevitability of a wave breaking softly on the shore. It also can be all too painfully obvious and emphatic, slashing the value of our assets before our eyes.

I was not around for the hyperinflation in Germany following World War I, when people paid for bread and milk with suitcases full of paper money. As a member of the generation born on the eve of World War II, I can, however, recall another dramatic example of big-time inflation right here at home -- one involving not luggage, but radio and TV.

Back in the 1940s, in my pre-adolescent years, I sometimes matched wits with contestants on a show called "The $64 Question" on my Philco radio set. Less than a decade later, in the mid-1950s, inflation -- combined with hype -- had raised the stakes spectacularly, giving rise to a TV show called "The $64,000 Question."

I mention all this by way of leading up to a numismatic drama that unfolded yet another decade later, smack in the middle of the turbulent 1960s. The preamble is relevant, however, for the drama has come to be known in coin-collecting circles as "The '64-Dollar Question." And the coin around which it revolves could very well be worth $64,000 -- possibly even $640,000 -- if it ever appeared on the market.

That coin is the 1964-D Peace dollar -- and it is, without much doubt, the single most valuable U.S. coin struck in the last 65 years, or since the production and immediate withdrawal of the 1933 double eagle.

How much is it worth? That's hard to say, since there never has been a published report of any being sold. Some would even question whether any examples remain in existence today.

There's little question, though, that this coin did exist at one time -- in fact, that hundreds of thousands were produced. And the strange circumstances surrounding its birth and subsequent disposition only serve to heighten its allure.

It's widely believed that if any examples still survive today -- and if they can escape the threat of confiscation -- they might very well bring prices in the six-figure range. But, like so many of the facts and figures having to do with this coin, that falls under the heading of pure conjecture.

More than 33 years have passed since the '64 Peace dollar came into being in the late spring of 1965. However, the passage of time has shed little new light on this fascinating numismatic enigma.

Many are perplexed as to why the coin was minted in the first place. The timing was curious, to say the very least; in fact, it hardly could have been worse.

Consider what the circumstances were in August 1964, when the silver dollar proposal came before Congress for a vote:

The nation was in the grip of a prolonged coin shortage.

The government's silver stockpile was shrinking rapidly, as rising silver prices triggered widespread hoarding of silver coins.

And coin collectors and speculators had stripped the Treasury's vaults of virtually all the reserves of silver dollars.

Against this dismal backdrop, a new silver dollar was just about the last thing the government needed. Yet, under pressure from President Lyndon B. Johnson, Congress threw logic out the window and authorized the production of 45 million silver dollars. To get the ball rolling, it appropriated $600,000.

While there may not have been a logical explanation, there WAS a certain amount of political expediency behind this ill-conceived action.

Evidently, the realities of the silver shortage hadn't yet been fully grasped in Washington, and many members of Congress felt that the silver dollars siphoned from the Treasury ought to be replaced. This sentiment, it appears, was reinforced by demands from Western lawmakers, who argued that silver dollars were needed in the commerce of their region.

These legislators pressed their case with the president -- and once LBJ gave the proposal his blessing, his legendary arm-twisting skill all but assured the measure's passage.

The folly of this was underscored only a few weeks later, when the worsening coin shortage prompted Congress to authorize a date freeze: All coins struck after Dec. 31, 1964 would continue to be dated 1964 in an effort to discourage hoarding. But, even then, Congress stopped short of scuttling the new silver dollar.

Confronted simultaneously with shortages of smaller coins and dwindling stocks of silver, Treasury officials balked at starting production of the newly authorized cartwheel. They did so with the backing of key members of Congress who had fought against the proposal from the start.

But Western senators and congressmen continued to press for action -- and finally, on May 15, 1965, LBJ issued a presidential order directing that production begin without further delay.

During the days that followed, well over 300,000 silver dollars were struck at the Denver Mint. These included 30 trial strikes and 316,076 business strikes, presumably meant for use in circulation.

The Treasury has sought to keep a tight lid on details of this production. Despite this, numismatic sleuths have learned a great deal of pertinent information.

It is known, for example, that the coins were identical in design and composition to the Peace dollar, the last previous U.S. silver dollar, whose production had been halted in 1935. That means they were 90-percent silver.

It also has been determined that the coins were dated 1964, rather than 1965, in compliance with the date freeze then in effect. And according to at least one published report, they carried a "D" mint mark.

Why all the secrecy? Why not let those hundreds of thousands of coins speak for themselves?

As far as Uncle Sam is concerned, those coins never really existed. All 316,106 of them (counting the 30 trial strikes) were -- or should have been -- consigned to the melting pot.

Let's return to 1965. The White House, it turned out, was overruled by Congress. When word of the coins' production got back to congressional opponents, they angrily demanded immediate suspension of the program. And Mint officials cheerfully complied.

The Mint was convinced that the coins would never circulate -- and evidence suggests that it was right. Before a single '64 silver dollar could be issued, coin dealers -- anticipating their release -- already were running ads offering them for sale at prices as high as $7.50 a piece.

They never got to fill any orders. The fact is, the Mint never did issue a single '64 dollar. Orders went out from Washington that no further dollars should be struck, and that those already made should be melted -- and Denver Mint officials carried out those orders conscientiously.

How, then, could any of the coins have survived? The explanation lies in the manner of the melt.

Following standard procedure, Denver Mint technicians verified the number of coins being melted by weighing them on a quantity basis, rather than examining each one individually. This saved time and cut costs, but it also opened the door -- quite literally -- to possible removal of some of the coins from the mint.

One or more employees might very well have removed a few of the new coins and substituted specimens of older silver dollars. That way, the total weight still would have been correct, and the substitution might very well have gone unnoticed.

Undoubtedly, the Mint had other safeguards in place to avert such an occurrence. Eva B. Adams, the Mint director at the time, said the '64 dollars were "most carefully guarded to avoid a loss." She went so far as to say that "none of the coins ever left the mint."

But how could she -- or anyone -- really be sure? A few years later, entire bags of coins were stolen from the Philadelphia Mint, a much more modern facility, in spite of sophisticated security measures.

There's also a good chance that some of the silver dollars may have gotten out through official channels. Persistent rumors have it that presentation pieces were given to President Johnson and certain members of Congress -- and while the Mint has always denied such reports, cynics point out that the government once denied ever having produced the coins in the first place.

That denial was contained in a Treasury Department press release dated May 24, 1965. The Mint, it said, "will not make any ... dollars at this time" -- conveniently failing to mention that it had already produced more than 300,000.

There's documented evidence that at least two 1964 dollars survived until 1970. According to Mint records, 28 of the 30 trial strikes were melted immediately -- but the other two were sent to Washington for optical, physical and spectrographic examination and remained there, in a Treasury vault, until the spring of 1970. At that time, the records show, they were melted. Four members of a destruction committee signed affidavits attesting to this.

For a time, the '64 dollars all but disappeared from the hobby's consciousness. Then, in 1972, a commodities market newsletter reported that such dollars had indeed been produced -- and that some of them had escaped into private hands.

By interesting coincidence, that report appeared just about the time the seven-year statute of limitations presumably would have expired for federal prosecution of anyone who removed these coins from the mint.

In April 1973, Maryland coin dealer Bob Cohen placed a full-page ad in The Numismatist, the official monthly journal of the American Numismatic Association, offering to pay $3,000 for a specimen of the coin. Cohen reported that the ad generated a number of intriguing responses and even tentative offers -- but no actual coins.

A major reason for that, it would appear, was a press release issued by the Mint on May 31, 1973. In it, the bureau declared that since the '64 dollars were never officially issued, any such coins found in the possession of private individuals "are the property of the United States, which is entitled to recover [them]."

"Right after the ad appeared, I had an offer of five pieces at $5,000 each," Cohen said, "and I'm convinced it was legitimate. But then the government came out with all the publicity that the coins were illegal, and I never heard any more. The people evidently got scared."

Since then, most observers familiar with the matter have likened the '64 dollar to the 1933 double eagle ($20 gold piece) -- a coin which was also officially struck but not, in the government's view, officially issued. The Secret Service has indeed resorted to confiscation in the case of the '33 double eagle -- so anyone holding a '64 dollar would be understandably hesitant to bring it out of hiding, at least until and unless the stigma is removed by the Mint.

Harry J. Forman, a well known coin dealer from the Philadelphia area and author of several books on coin investment, has no doubt that '64 silver dollars may exist, but doubts whether any will surface -- at least in this country.

"None has turned up for 33 years and none may turn up for 33 years more," Forman said. "If one of these coins ever did turn up, I think it would be seized and in all probability placed in the Smithsonian. That's my guess.

"I don't think it would ever be ruled legal," he went on, "because there would be questions about how it got out of the mint. There would always be a cloud over the coin."

Collectors' best chance of seeing a '64 dollar -- or at least an illustration -- would be if one turned up overseas, Forman said.

"If one did get out, my suspicion would be that it would be out of the country," he remarked. "And if one of these coins turned up in an auction in Switzerland, I don't know whether the U.S. could get it back; after all, it sometimes has trouble extraditing criminals and bringing them back from abroad -- much less coins."

For now, there are many more questions than answers, and the 1964 Peace dollar remains a coin of mystery.

Do any examples exist? If so, where are they hidden? Is there any chance that the Mint might lift its ban? And if the ban were lifted, what would the coins be worth?

Those, to coin a phrase, are '64-dollar questions.