Materials glossary / Organic material
Pearl
On the label: Pearl · Organic material
What it is
Nacre (calcium carbonate and protein) laid down by a mollusk. Almost all pearls sold are cultured (a bead or tissue nucleus is implanted); natural pearls are rare and auctioned. Mohs 2.5 to 4.5: soft, damaged by acids, perfume and heat.
Organic materials: Materials made by living things: pearls, amber, coral, shell, jet, bone. Softer than mineral stones and sensitive to acid, heat and perfume.
In the research
308 PubMed papers mention it with jewelry, allergy, eyewear or UV; the three most recent:
- Best formulas for highly myopic patients (axial length ≥26 mm) receiving cataract surgery · Current opinion in ophthalmology, 2026
- Efficacy of Total Keratometric Power and Total Corneal Power on the Accuracy of 8 Modern Intraocular Lens Formulas in Highly Myopic Eyes · Journal of refractive surgery (Thorofare, N.J. : 1995), 2026
- Prediction error in low power intraocular lens in highly myopic eyes · BMC ophthalmology, 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 organic materials
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.