Agate
On the label: Agate · Gemstone
What it is
Banded chalcedony (microcrystalline quartz) in many colors, Mohs 6.5 to 7; bright pinks, blues and greens are dyed.
Gemstones: Natural gemstones, as mined and cut. Hardness (Mohs scale) says what scratches what; treatment (heat, oil, dye) must be disclosed under FTC rules.
In the research
6 PubMed papers mention it with jewelry, allergy, eyewear or UV; the three most recent:
- Forensic characterization of Brazilian gemstones: A pilot study employing raman spectroscopy and multivariate analysis · Forensic science international, 2025
- Jewelry rock discrimination as interpretable data using laser-induced breakdown spectroscopy and a convolutional LSTM deep learning algorithm · Scientific reports, 2024
- Guideline (S2k) on acute therapy and management of anaphylaxis: 2021 update: S2k-Guideline of the German Society for Allergology and Clinical Immunology (DGAKI), the Medical Associ · Allergo journal international, 2021
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
12 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.