The Atlas · Gold fineness mark
585 means 14 karat gold: 585 parts gold in every thousand, 58.5% gold by weight. It is the continental European way of writing exactly what an American maker stamps 14K, and it is real gold, not plate.
What does 585 mean on a ring? — answered here in full, free, with nothing asked of you.
Continental Europe stamps gold in parts per thousand; Britain and America stamp it in karats out of twenty-four. 585 and 14K are the same metal written in two notations, and a piece marked 585 is worth the same per gram as a piece marked 14K. If a ring in the box is stamped 585 and its neighbour is stamped 14K, you are almost certainly looking at one European piece and one American one, not at two different qualities of gold.
What the number does not tell you is who checked it. In Britain a fineness mark sits beside a town mark and a date letter because an assay office physically tested the metal. On most continental and all American work, the fineness stamp is the manufacturer's own declaration — usually honest, occasionally wrong, and worth nothing at all on a modern counterfeit. A 585 accompanied by other marks is much stronger evidence than a 585 standing alone.
For an estate box the practical consequence is arithmetic. 585 sets the gold fraction; the piece's weight sets everything else. A 2-gram 585 charm and a 34-gram 585 bracelet carry the same stamp and differ by a factor of seventeen in melt value, so a kitchen scale is worth more to you here than any opinion.
The stamp is present and legible: somebody declared this metal as 14 karat gold, 585 parts per thousand.
Continental European manufacture, most commonly from the 1930s onward. A second mark beside it — a crown and crescent, an assay office punch, a maker's initials in a shaped shield — usually narrows this to a country and often to a decade.
Whether the whole piece is 585 throughout. A photograph cannot see a gold shell over base metal, a plated repair, or a steel spring inside a clasp, and it cannot weigh the piece — and weight is what turns a fineness mark into a number of dollars.
Next step
Photograph the inside of the band with the phone's macro or a jeweller's loupe held over the lens, and weigh the piece on a kitchen scale to the nearest gram. Those two facts together turn 585 from a label into a floor price.
Soviet 14 karat, 583/1000 under the pre-1994 standard. Slightly less gold, and a strong signal of Russian or Soviet-era origin.
9 karat, 375/1000. Barely more than a third gold — under half the melt value of 585 at the same weight.
18 karat, 750/1000. Nearly a third more gold per gram than 585.
Not solid gold. Those letters mean heavy gold electroplate, gold plate, gold filled or rolled gold plate — a gold skin over base metal, with the fineness describing only the skin.
Free, and nothing asked of you
One mark answers one question. A box answers the real one — which pieces deserve money and expertise, and which nine are costume. Email the photographs to the house inbox: the whole box laid out, then any stamps you can find. We read them and reply by hand.