Colección 14K

Karat measures how much of a metal is gold, in twenty-fourths. 14K means fourteen parts gold to ten parts other metals - a little under three-fifths gold by weight.

The remaining parts are alloy metals such as copper, silver and zinc, and for white gold, metals like palladium or nickel. They are what give the gold enough hardness to be worked into a setting and worn.

14K is the karat most American fine jewelry is made in, which is why it is the largest part of this collection.

Because pure gold is too soft to hold a shape or a stone. At 24K it bends and marks very easily, which makes it impractical for a ring, a clasp or a fine link.

Alloying with copper, silver, zinc or white metals gives gold the working hardness it needs. It is what turns gold into a material a jeweller can actually build with.

The alloy also decides the colour. Yellow, white and rose gold all start from the same metal and differ only in what is mixed with it.

The gold content is the same at a given karat - only the alloy differs. Yellow gold is alloyed to stay close to gold's own colour. Rose gold carries more copper, which is where its warmth comes from.

White gold is alloyed with white metals to neutralise the yellow, then usually plated with rhodium for a brighter, cooler white. That plating is a surface layer, and it wears over time; a jeweller can reapply it.

Because the colour of yellow and rose gold is in the alloy rather than on the surface, neither has plating to maintain.

None of them is better in the abstract - they sit at different points on the same scale and answer different priorities.

18K holds more gold, so the colour is richer and deeper, and the metal is softer. 10K holds less gold, so it is paler and cooler in colour, and harder.

14K sits between them, which is why it became the American default: a recognisably golden colour in a metal that is practical to work and to wear.

Two-tone combines two gold colours in one piece, most often yellow with white. Tricolor uses all three - yellow, white and rose - together.

The colours come from different gold alloys rather than from plating, so they are part of the metal itself and will not wear off.

They are also practical: a piece that already contains more than one colour sits comfortably next to whatever else the wearer owns, which is why multi-colour designs are so widely worn.

Gold itself does not tarnish. What can react over time are the alloy metals mixed with it, particularly where copper is involved.

In practice that shows up as a slight dulling rather than the blackening associated with silver, and it is usually the result of contact with cosmetics, lotions, chlorinated water or household cleaning products.

Taking pieces off before swimming and cleaning, and washing them occasionally in warm soapy water, prevents almost all of it.

It gives white gold a brighter, cooler white than the alloy achieves on its own. Alloying gold with white metals removes most of the yellow but rarely all of it, so a thin rhodium layer is applied over the surface.

Because it is a surface finish, it wears with use - soonest on the parts of a piece that get handled most, such as the underside of a ring.

A jeweller can reapply it, and how often depends entirely on how hard the piece is worn. Yellow and rose gold have no equivalent maintenance.

Yes. 14K is a standard working metal and any competent jeweller will size a ring, shorten a chain or replace a clasp in it.

Whether a particular piece can be resized depends on the design rather than the karat - a ring set with stones all the way around is difficult in any metal.

It is worth telling a jeweller the karat and the gold colour before a repair, so the solder they use matches the piece.

The karat fixes how much gold is present, not what the remaining metal is. Manufacturers use their own alloy recipes, varying the balance of copper, silver and zinc, and each recipe produces a slightly different yellow.

Finishing accounts for the rest. A high polish reads brighter than a satin or matte surface on the same alloy, and a piece that has been worn for years carries a softer surface than one straight from the case.

The practical consequence is that pieces bought at different times may not match exactly. Where an exact match matters, buying the pieces together is the surest route.

Warm water, a little mild soap and a soft brush, then a thorough rinse and a soft cloth. Nothing more elaborate is needed for the metal.

Where a piece is stone-set, the stone decides what is safe rather than the metal - avoid ultrasonic and steam cleaning on anything with a coloured stone.

Keep gold away from chlorine and household cleaning chemicals, and store pieces so that harder items are not resting against softer ones.