The $4 Stella — the gold coin America designed but never spent

In the 1870s, money did not travel well. An American crossing into France, Germany, or Italy carried gold coins that no shopkeeper there could value at a glance. Each country minted its own pieces to its own weight, and money-changers took a cut at every border.

A group of European nations had a fix: the Latin Monetary Union, a treaty that locked their gold and silver coins to a shared standard so a French franc, an Italian lira, and a Swiss franc all weighed the same in metal. It was, in a real sense, the euro a century early.

Some Americans wanted in. The push is usually credited to John A. Kasson, a former chairman of the House committee on coinage who was then serving as U.S. minister to Austria-Hungary. His idea was a small American gold coin sized to slot neatly into that European system — a piece a traveler could spend abroad without losing money to the exchange. Four dollars was the sweet spot: close in gold value to the French 20-franc Napoleon and its cousins across the continent.

There was a second idea riding along. A Philadelphia inventor, Dr. William Wheeler Hubbell, had patented an alloy he called goloid — gold stretched with a little silver and copper, meant to make a gold coin in a more convenient size. The Stella was supposed to test both notions at once: a new denomination and a new metal.

So the Mint struck patterns — trial coins, not legal money — in 1879 and again in 1880, all at Philadelphia. The plan was to put them in front of Congress and let the lawmakers decide. Congress looked, and said no. The United States never joined the Latin Monetary Union, goloid never became coinage, and the four-dollar piece died as an experiment. The handful that were struck are all that the idea left behind.

The coin got its name from its back. Stella is Latin for star, and the reverse — the tails side — is dominated by a single large five-pointed star. Across the star reads ONE STELLA / 400 CENTS, ringed by the mottos E PLURIBUS UNUM and DEO EST GLORIA ("To God be the glory"). That reverse was the work of Charles E. Barber, the Mint's chief engraver.

The obverse — the heads side — is where the coin splits in two. It shows Liberty facing left, and the Mint tried two different heads.

• The Flowing Hair type, with Liberty's hair streaming loose, was engraved by Charles E. Barber.
• The Coiled Hair type, with the hair gathered in a tight braided coil, was engraved by George T. Morgan — the Englishman whose Liberty already stared out from the Morgan silver dollar.

Around Liberty's head runs one of the strangest legends ever placed on a U.S. coin: 6 G .3 S .7 C 7 GRAMS. It is a recipe. It tells you the coin is supposed to contain 6 grams of gold, 0.3 of silver, and 0.7 of copper, for 7 grams total — Hubbell's goloid alloy, written out in the metric language of the European union it hoped to join.

Here's the catch that delights collectors: the surviving Stellas were not struck in goloid. They were made in the ordinary U.S. gold standard of the day — 90% gold, 10% copper — even though the coin's own face advertises a different metal. The piece describes an alloy it isn't made of. Each one weighs about 7 grams and measures roughly 22 millimeters across, with a reeded (grooved) edge, and every example was made as a proof — a specially polished strike from carefully prepared dies, meant for inspection rather than spending.

There are four Stellas a collector can chase, and they are wildly unequal in survival.

The 1879 Flowing Hair is the one you actually see. The traditional mintage figure is 425, though some researchers put the real number higher because the Mint quietly restruck the design after demand spiked. It is rare and expensive — but it exists in enough numbers to anchor most museum cases and high-end collections, and it is the version most people picture when they hear "Stella."

The other three are different animals entirely. The 1879 Coiled Hair is thought to survive in roughly a dozen to sixteen pieces. The 1880 Flowing Hair is scarcer still, with the grading services having certified only a couple dozen. And the 1880 Coiled Hair — George Morgan's braided Liberty, dated 1880 — is the prize: experts estimate fewer than a dozen exist, perhaps eight to ten. In 2013 a single 1880 Coiled Hair graded NGC PF 67 Cameo sold for $2.57 million at Bonhams, the first Stella ever to clear a million dollars and still a benchmark for the series.

Because every Stella is a proof and most never circulated, the grading conversation is unusual. These coins were handled as keepsakes, not spent, so many survive in high grade. But that same history left scars: a number of Stellas turn up with a tiny hole drilled at the top, because they were mounted as jewelry and worn. A holed or harshly cleaned example sits far down the value ladder from an untouched cameo proof. With a population this small, condition and originality are most of the price.

That jewelry detail feeds the Stella's most repeated story. Collectors love to say the coins ended up as necklaces worn by the madams of Washington's high-end brothels — pieces handed out to congressmen for "study" that found a livelier afterlife. It's a wonderful tale, and the drilled examples are real. But treat it as legend, not record: the story is usually traced to the numismatic writer Walter Breen, and serious researchers are skeptical of the details. The Mint did not keep tidy accounts of where every restrike went, which is exactly the kind of gap a good anecdote grows in.

One more thing worth knowing: precise Mint records for the Stellas are incomplete, especially for the restrikes. Reputable sources give ranges, not exact counts, for the rarest three varieties. Anyone quoting a single hard number for, say, surviving 1880 Coiled Hairs is rounding off uncertainty.