# Coral, red (Corallium rubrum)

**Corallo rosso**

**Known today as.** Precious red coral, *Corallium rubrum*, of the western Mediterranean, prepared as powder.

Kind: Animal  
Qualities: Cold, dry, and binding (Culpeper).

## What did Canale use it for?

In a powder, and tied about the neck to prevent bewitchment, “according to Dioscorides” (chs. 6, 10).

## What does modern science say?

Long prized for jewelry.

## Pharmacognosy and toxicology

- **calcium carbonate**: as calcite, the skeleton
- **magnesium**: in the calcite, which is high-magnesium
- **organic matrix**: 1–2 per cent, with over a hundred proteins

**Mechanism.** Powdered, it is calcium carbonate, the stuff of antacid tablets that relieve heartburn; tied at the neck it is a bead. Coral of another kind, the stony *Porites*, is used as a bone-graft substitute because its structure is like that of cancellous bone.

**Standing.** Overfishing and warming have shrunk its populations, and the IUCN classes it as Endangered.

## What lore surrounds it?

Branches of coral were hung at the necks of infants as a preservative, Pliny says, and English nurses in Elworthy’s day still fastened “the coral and bells” on a baby’s neck; in Italy, Elworthy found, a pendent horn of coral or metal was worn by nearly everyone against the evil eye.

## What did the older authorities say?

**Ovid.** In the *Metamorphoses*, Perseus lays the Gorgon’s head on seaweed, and the weeds harden at its touch; so coral, a plant in the sea, turns to stone out of it.

**Pliny.** Reports that coral hung on infants was held to protect them.

## Sources

- Ganot, P., et al. (2024). Genome sequence of the Mediterranean red coral *Corallium rubrum*. *BMC Research Notes* 17: 375.
- Le Roy, N., et al. (2021). The skeletome of the red coral *Corallium rubrum* indicates an independent evolution of biomineralization process in octocorals. *BMC Ecology and Evolution* 21: 1.
- Garg, V., Narang, P., and Taneja, R. (2022). Antacids revisited: review on contemporary facts and relevance for self-management. *Journal of International Medical Research* 50(3).
- Pliny the Elder. *Natural History* XXXII.11, trans. J. Bostock and H. T. Riley (1855). Perseus Digital Library.
- Ovid. *Metamorphoses*, Books I–VII, trans. H. T. Riley. Project Gutenberg ebook 21765.
- Elworthy, F. T. (1895). *The Evil Eye: An Account of This Ancient and Widespread Superstition*. London: John Murray.
- Culpeper, N. (1653). *Pharmacopoeia Londinensis: or the London Dispensatory*. London: Peter Cole. Text Creation Partnership edition A35381.
- Demers, C., et al. (2002). “Natural coral exoskeleton as a bone graft substitute: a review.” *Bio-Medical Materials and Engineering* 12.

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*Coral, red.* In *Materia Medica*, edited by B. C. P. Statema. Version 1, revised 2026-10-03. The Thinking Press. https://thethinkingpress.org/materia-medica/coral-red

Historical description, not medical advice.