Trothe Free ring sizer

Comparison

18ct gold or Anodised zirconium?

Anodised zirconium is meaningfully harder, so if your hands take a beating the choice is largely made for you.

18ct goldAnodised zirconium
Surface hardnessMohs 3Mohs 8.5
Density15.6 g/cm³6.5 g/cm³
ResizableYesReplaced free
HallmarkedYesNot applicable
HypoallergenicAlloy dependentYes
Price from£795£195

What the difference actually feels like

18ct gold is 2.4 times the weight of anodised zirconium for the same ring. On paper that is a number; on the hand it is the difference between a ring you forget about and one you are aware of every time you move. Neither is better. It is worth knowing which you want before you spend anything.

Anodised zirconium sits at Mohs 8.5 against 3. Ordinary household dust carries quartz at Mohs 7, which is the line that matters: below it a ring collects fine scratches from nothing more than daily life. That is not a marginal difference between these two, it is the main one.

18ct gold can be resized and anodised zirconium cannot. Fingers change over decades, so this matters more than it seems at the point of buying. Our answer either way is that we cover it: a resize on one, a free replacement on the other, for as long as you own the ring.

The straight answer

Choose 18ct gold if depth of colour, or if weight on the finger.

Choose anodised zirconium if anyone who wants colour that will not wear off, or if hands that react to nickel.

Still torn? The metal chooser asks six questions and picks one, and it will tell you if neither of these is right.

In both materials

Rings to look at

Common questions

Is 18ct gold or anodised zirconium harder wearing?
Anodised zirconium, at Mohs 8.5 against 3. Airborne dust contains quartz at Mohs 7, so anything below that scratches from ordinary wear alone.
Which is heavier?
18ct gold, at 15.6 g/cm³ against 6.5. That is 2.4 times the weight, which is very obvious on the hand rather than a technicality.
Can both be resized?
No. 18ct gold can be resized by any jeweller. Anodised zirconium cannot, so we replace it free for life instead.
Which costs more?
18ct gold, starting at £795 against £195. That is about 308% more before any stone or inlay.
Are both hallmarked?
Only 18ct gold. Anodised zirconium is not a precious metal, so no hallmark exists for it.