9, 14 or 18 carat gold: which to choose

Every piece of the house comes in three gold carats: 9, 14 and 18. Here is what separates them.

What carat means for metal

Applied to metal, the carat measures the proportion of pure gold out of twenty-four parts. It should not be confused with the carat of stones, which is a unit of weight equal to 0.2 grams.

CaratPure goldHallmark (parts per thousand)
9 carat37.5 %375
14 carat58.5 %585
18 carat75.0 %750

The remainder is alloy — copper, silver, palladium — which gives the metal its tone and its mechanical properties.

Colour

The higher the carat, the warmer and deeper the tone. Eighteen carat gold has the deep yellow associated with the great houses. Fourteen is slightly lighter. Nine is the palest of the three — discreet, and often read as more contemporary.

In white gold the difference in tone is masked by rhodium plating. It reappears as the plating wears, after some years of wear: 18 carat white gold then turns slightly champagne, while 9 carat stays cooler.

Hardness

Counter-intuitively, the purer gold is the softer. An 18 carat band scratches and distorts more easily than a 9 carat one, whose alloy is harder. On the other hand, 9 carat gold, richer in copper, is more prone to tarnishing over time and lends itself less well to certain repairs.

For a ring worn every day, including at work, 14 carat is the best compromise: hard enough to withstand wear, rich enough to keep its colour.

Price

The difference in price between the three carats reflects the quantity of pure gold used. For an identical design, moving from 9 to 18 carat roughly doubles the price of the piece. The stone does not change.

Hallmarking

All our pieces are in solid gold — never plated, never vermeil — and carry the mark of their fineness in parts per thousand. That is what you should look for inside any gold jewel: 375, 585 or 750.

In short

  • 9 carat — the hardest, the palest, the most affordable. For a first piece or for heavy wear.
  • 14 carat — the balance. Our default recommendation for a ring worn every day.
  • 18 carat — the richest colour and the fullest weight. For a ceremonial piece or one meant to be passed on.

Hesitating? Write to us at carronetolivier@gmail.com: we will tell you what we would recommend for the use you have in mind.