Tungsten carbide
On the label: Tungsten carbide · Metal
What it is
A ceramic-metal compound of tungsten and carbon, the hardest material used for rings (about 9 on the Mohs scale). It does not scratch but can shatter if struck, and cannot be resized. Some grades use a cobalt binder that can irritate skin; nickel-bound grades are the jewelry standard.
Metals: Solid metals: what the piece is made of all the way through. Purity is written as karat (gold) or parts per thousand (925 silver, 950 platinum).
In the research
26 PubMed papers mention it with jewelry, allergy, eyewear or UV; the three most recent:
- Impacts of clean-up visualization techniques on excess composite of orthodontic attachments · Journal of orofacial orthopedics = Fortschritte der Kieferorthopadie : Organ/off, 2026
- Properties of Tungsten Carbide Rings When Compressed to Failure or Cut with a Diamond Grinding Bit: A Biomechanical Study · The Journal of bone and joint surgery. American volume, 2025
- Fluorescence-aided identification technique using a low-cost violet flashlight and rotatory instruments for dental trauma splint removal · Dental traumatology : official publication of International Association for Dent, 2023
A paper is a paper, not a verdict: titles are listed so you can read them, and a study on one fabric or one filter says little about the piece in your hand.
Other metals
Clasp & Lens describes materials from the public record and does not appraise, grade or test pieces; what a listing states is the supplier's statement. If a piece causes a rash, take it off; a reaction that spreads or blisters is a doctor's question, and sunglasses are no substitute for impact-rated eye protection where that is required.