Where to find the 585 stamp
Locate the hallmark before you think about prices. On rings it sits inside the band, usually next to the maker's mark. On chains and bracelets it is struck onto a small tag beside the clasp, on earrings onto the butterfly back or the post. The stamp is tiny — on older pieces you will often need a loupe, because decades of wear polish it down. Alongside 585 you may see „14k" or „0.585", which mean exactly the same thing.
What the number actually states
Purity is expressed in parts per thousand. 585 therefore means 585 parts pure gold out of a thousand, or 58.5%. The remaining 41.5% is copper, silver, sometimes palladium or nickel — these give the alloy hardness and determine its colour. The carat scale describes the same thing differently: pure gold is 24 carat, and since 14/24 works out to roughly 58.5%, the 585 hallmark equals 14 carat.
Worked example: gold content in a ring
A specific piece makes this concrete. A typical women's wedding band weighs about 5 grams. At 585 purity it contains 5 × 0.585 = 2.93 g of pure gold. The rest is alloy with no buying value. This is precisely why nobody pays for the full weight of a piece, only for its gold share. A 9-gram men's ring yields 5.27 g of pure gold; a slim 2.4-gram chain only 1.4 g.
The buying range for 14 carat
We buy 14 carat gold at an indicative 1,250–1,780 CZK per gram. The range is not arbitrary — its upper and lower bounds shift with the current market price of gold and with the condition of the individual piece. How a market quote becomes the figure on your receipt is set out step by step in How the gold buying price is calculated. Ranges for every other purity — 333, 750, 900 and 999 — are listed in the buying price list.
White 585 is not the poor relation
White gold is made by alloying palladium or nickel instead of copper and then plating the surface with a thin layer of rhodium. The purity is unchanged — 585 is 585 regardless of colour. A white and a yellow 14 carat ring therefore fetch comparable amounts per gram. Rhodium plating wears away over time and the piece starts to show yellow underneath; this does not affect the price, because the plating is a surface finish of negligible weight.
When the hallmark is missing or unreadable
An absent stamp does not mean the piece is not gold. A hallmark can be lost when a ring is resized, imported pieces were sometimes never struck at all, and older Czech jewellery carries purities such as 900 or 986 that are no longer in common use. In those cases we measure the purity at the counter with a non-contact tester — the piece takes no damage and the result comes through in moments. We use the same check to confirm or rule out gold-plated costume jewellery carrying a fake stamp.
Have 14 carat pieces at home and want to know where you stand? Call in at Kotlářská 28, Brno-střed — we measure purity and weight free of charge and quote the buying price on the spot, with no obligation to sell.
