Diamond
On the label: Diamond · Gemstone
What it is
Crystalline carbon, the hardest natural material (Mohs 10). Graded by the 4Cs: carat weight, cut, color (D to Z), clarity. Natural diamonds are mined; see lab-grown diamond for the identical lab material.
Gemstones: Natural gemstones, as mined and cut. Hardness (Mohs scale) says what scratches what; treatment (heat, oil, dye) must be disclosed under FTC rules.
Wikidata: Allotrope of carbon often used as a gemstone and an abrasive. Q5283 →
In the research
450 PubMed papers mention it with jewelry, allergy, eyewear or UV; the three most recent:
- Geometry-Programmed Connectivity Enables Predictive Assembly of Diamond-Family Colloidal Crystals · Journal of the American Chemical Society, 2026
- Diamond compound refractive lenses for high-energy dark field X-ray microscopy · Journal of synchrotron radiation, 2026
- Chemical Design Rule for Ultraviolet-Emitting Color Centers: The Role of Host Ionicity · Journal of the American Chemical Society, 2026
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.
Pieces whose listing names it
24 on the siteMatched from the words in the supplier's listing; the full material line is on each product page.
Made in the USA
Made in the USA
Made in the USA
Made in the USA
Made in the USA
Made in the USA
Made in the USA
Made in the USA
Other gemstones
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.