Trothe Free ring sizer

Contemporary metal

Black zirconium

Black all the way through the surface

Surface hardnessMohs 8.5
Density6.5 g/cm³
ResizableReplaced free
HallmarkedNot applicable

The same oxide process taken to its end point. Heated in air, zirconium forms a genuinely black ceramic surface that is part of the metal rather than a coating over it. Black plating on a steel or tungsten ring wears through at the knuckle within a year or two. This does not, because there is nothing to wear through to.

Right for

  • Anyone who has had a plated black ring wear through
  • Manual work
  • A ring that should look quiet

Wrong for

  • Anyone who wants to resize it later

Honestly

Deep scratches can reach past the oxide to the pale metal beneath. It takes a real impact, not ordinary wear, and we will refinish it free.

In this material

9 rings

Weighing it up

Compare it against something else

Black zirconium questions

Can a black zirconium ring be resized?
No. Black zirconium cannot be stretched or cut and rejoined the way precious metals can, and anyone claiming otherwise is describing a replacement. We replace free for life instead, which is the same outcome stated honestly.
Is black zirconium hard wearing?
Its surface sits at Mohs 8.5. For comparison, airborne dust contains quartz at Mohs 7, which is why anything below that picks up fine scratches from ordinary wear. This is comfortably above that line.
Is black zirconium hallmarked?
No, and it does not need to be. The Hallmarking Act applies to gold, silver, platinum and palladium. Black zirconium is not a precious metal, so no hallmark exists for it and none is required.
How heavy is a black zirconium ring?
6.5 grams per cubic centimetre. Titanium is the lightest thing we make at 4.5 and platinum the heaviest at 21.4, so this sits at the light end of the range.
Is black zirconium safe for sensitive skin?
Yes. It contains no nickel, which is the metal that causes almost all jewellery reactions.