Materials glossary / Organic material
Coral
On the label: Coral · Organic material · a rule or standard applies
What it is
The calcium carbonate skeleton of certain corals, red to pink; Mohs 3 to 4. Precious red coral is CITES-regulated and most 'coral' in fashion jewelry is dyed bamboo coral or resin.
Organic materials: Materials made by living things: pearls, amber, coral, shell, jet, bone. Softer than mineral stones and sensitive to acid, heat and perfume.
Wikidata: Ridge of rock in the sea formed by the growth and deposit of coral. Q11292 →
In the research
251 PubMed papers mention it with jewelry, allergy, eyewear or UV; the three most recent:
- Dynamic nutrient competition (de-)stabilizes photosymbiosis · mSystems, 2026
- Seabirds and native vegetation drive ecosystem processes that support atoll island resilience · Science advances, 2026
- Blocks of Identity by Descent Reveal the Dual Role Played by Reef Fish Larvae for Retention and Dispersal · Molecular ecology, 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
1 on the siteMatched from the words in the supplier's listing; the full material line is on each product page.
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.