Real precious coral shows a fine, straight grain under a loupe, like the grain in a piece of wood, running the length of each bead or along the branch of a carving, and on a cut end you can see faint concentric rings with a tiny radial pattern around a central point. It feels cool and surprisingly heavy for its size, takes a soft, slightly waxy polish rather than a glassy one, and the color is never perfectly uniform: look closely and there are paler streaks, a slightly lighter core or a faint mottling. Plastic shows mold seams and feels warm and light. Glass shows round bubbles and swirls and feels cold and slick. Dyed bamboo coral, which is the most common substitute by far, shows dye pooled in cracks and pits, a dark line at the drill holes, and comes off red on an acetone swab. Those checks sort nearly every necklace and cameo at home. Which species it is, whether the color has been enhanced and whether it can be shipped across a border are questions for a gem lab and the trade rules.
Quick answer
- Real coral: fine parallel grain, concentric rings on a cut end, cool, heavy, waxy polish, slightly uneven color, no bubbles.
- Dyed bamboo coral: dye in cracks and drill holes, acetone swab turns red, visible pits.
- Plastic: warm, light, mold seams, acrid smell from a hot needle. Glass: bubbles, cold, chips.
- Values as of late 2026: about $5-30 for a dyed bamboo strand, $150-800 for a good antique Mediterranean red strand, $500-3,000 and up for fine oxblood or angel skin.
How to check yours, step by step
- Find the grain. Under a 10x loupe in good light, real Corallium coral shows fine, straight, parallel striations running along the length of the branch, visible on beads as faint lines that all run the same way around the drill axis. On a flat cut surface, such as the back of a cameo or the base of a carving, the lines become concentric rings around a tiny center, like a tree trunk in section, with a faint spoke pattern between them. No grain at all points to plastic, glass or reconstituted coral; a pattern of pores or channels points to bone or sponge coral.
- Check the weight and feel. Precious coral is calcium carbonate with a density of about 2.6 to 2.7, which is heavier than almost every imitation. A strand of real coral beads has a noticeable heft and feels cool against the wrist. Plastic, celluloid and resin are light and warm. Glass is as heavy but colder and slicker to the touch.
- Swab with acetone. Nail polish remover on a cotton bud, held against the back of a bead or in the drill hole for ten seconds. Real, undyed coral gives nothing. Dyed bamboo coral, dyed bone and dyed shell leave red or orange on the swab. This is the most useful single test, because dyed bamboo coral is most of what is sold as red coral today.
- Look at the drill holes and cracks. Dye concentrates where the surface is broken. Dark red rings at the drill holes and in surface cracks mean dye. Bamboo coral also shows the dark, pitted, slightly fibrous texture of its skeleton, and on larger beads the natural dark bands of the bamboo stem where it was not fully bleached.
- Hunt for bubbles and seams. Round bubbles or swirled streaks inside mean glass. A fine raised line running around a bead, or across the back of a carving, is a mold seam and means plastic or pressed coral. Natural coral has neither.
- The hot needle, only on a hidden spot. Touch a heated pin to the inside of a drill hole. Real coral does not react beyond a tiny chalky mark. Plastic melts and smells acrid, celluloid smells of camphor, and the pin sinks in. This is destructive and should only be done where it cannot be seen.
- The vinegar drop, only on a hidden spot. One drop of white vinegar on the back of a piece fizzes very faintly on real coral and on shell and bone, because all three are calcium carbonate or contain it. It does nothing on plastic or glass. Wipe it off at once. It separates the organic group from the artificial, but not coral from shell.
- Read the color pattern. Natural red and pink coral shows subtle variation: a slightly paler center on beads, faint longitudinal streaks, occasional small white spots. Dyed material is uniform. Angel skin, the pale pink grade, often shows a faint blush gradient. Reconstituted coral, made of ground coral powder set in resin, shows a speckled, granular look under the loupe and an even color overall.
What coral sells for
Precious coral comes from a handful of deep-water species: Corallium rubrum from the Mediterranean, which gives the classic red, and the Pacific species fished off Japan and Taiwan that give oxblood, momo (salmon and orange), and the pale pink boke sold as angel skin. The colors below assume natural, undyed material as of late 2026, because the species and the depth of color set the price more than anything else.
| What you have | Typical value, about | Notes |
|---|---|---|
| Dyed bamboo coral strand or bracelet | $5-30 | Most "red coral" sold since the 1990s; honest when labeled |
| Sponge coral, dyed, beads or pendant | $5-25 | Porous pattern, light, usually set in silver |
| Reconstituted or pressed coral | $5-40 | Coral powder in resin; granular look |
| Antique Victorian carved coral brooch or earrings, gold mounts | $150-700 | Value shared between carving, coral and the gold |
| Coral cameo, 1 inch, in 14k or 18k gold | $150-600 | Carving quality and mount set it; shell cameos are far cheaper |
| Mediterranean red bead necklace, 6 to 8 mm, antique | $200-900 | Graduated and well matched strands at the top |
| Oxblood (deep red) bead necklace, 8 to 10 mm | $800-3,000 | Dark, even red is the most sought color |
| Angel skin (boke) necklace, 8 to 12 mm, well matched | $1,000-5,000 | Evenly pale pink with no white spots is rare |
| Momo coral carving, figurine, 3 to 5 inches | $300-2,000 | Japanese and Chinese work; color and detail set the price |
| Branch coral necklace, rough twigs, natural red | $50-250 | Common tourist and 1970s pieces |
| Black coral bracelet or pendant | $20-150 | Regulated internationally; often hard to sell by post |
Large, deep oxblood pieces and fine carvings have climbed sharply because harvest is restricted and the old stock is what trades. At the bottom, the dyed bamboo strands that fill flea markets have barely moved. In mounted pieces, remember the metal: a Victorian coral brooch in 15k gold carries about $200-400 of gold at a gold price of about $4,000 per ounce as of late 2026, before the coral is counted, and our guide to how to read jewelry hallmarks shows how to read the mount.
Real coral versus the substitutes
| Point | Precious coral | Dyed bamboo coral | Plastic or resin | Glass |
|---|---|---|---|---|
| Grain | Fine parallel lines, concentric rings on cut ends | Coarse, pitted, with dark stem bands | None, or molded stripes | None, swirls |
| Color | Slightly uneven, paler core | Uniform, pooled in cracks | Perfectly uniform | Uniform or swirled |
| Acetone swab | Clean | Red or orange | Clean, may dull the surface | Clean |
| Weight and feel | Heavy, cool | Medium, cool | Light, warm | Heavy, cold |
| Drill holes | Clean, same color as surface | Dark dye rings | Clean, sometimes a lip of flash | Clean, chipped |
| Hot needle | No reaction | No reaction | Melts, acrid or camphor smell | No reaction |
| Vinegar | Faint fizz | Faint fizz | Nothing | Nothing |
| Typical price | $150-5,000 | $5-30 | $2-20 | $5-50 |
Bone and shell both pass the vinegar test and both get dyed red. Bone shows tiny dark pits and short dashes (the channels that carried blood vessels) rather than straight grain. Shell shows a flat, layered, slightly pearly structure, and the pink queen conch shell that is sold as "pink coral" shows a flame-like pattern on the surface that no coral has. A piece that passes the swab, the vinegar and the weight test and shows the straight grain is coral.
The legal side, plainly
Coral is one of the few jewelry materials where ownership and trade are tied to wildlife rules, and the rules differ by species and by country. Mediterranean red coral and the Pacific Corallium species are not on CITES Appendix I or II, so finished jewelry in those species trades without permits in most countries, though four Pacific species are on Appendix III at China's request and some countries ask for export paperwork. Black coral, blue coral and all the reef-building stony corals are on CITES Appendix II, which means an export permit for international shipment and, in the US, the possibility of seizure at the border without it. Within the US, old coral jewelry is legal to own and sell. The EU applies the same CITES listings and regulates harvest in the Mediterranean. None of this is legal advice; it is the reason a coral bracelet bought on holiday sometimes does not make it through the post.
How WorthPic reads coral photos
WorthPic runs on the newest and most capable AI model available, tuned for exactly this kind of identification. Photograph the strand or piece in daylight, a close-up of two or three beads or of the carved surface, the drill holes or the back, and the clasp or mount with any marks, and it reads the color and its evenness, whether grain or a pitted bamboo texture is visible, whether the drill holes show dye rings, the quality of the carving or the matching of the beads, and the metal of the mount. From that it names what the piece most likely is, with coral, dyed bamboo, sponge coral, glass, plastic and shell as the candidates, and gives an honest resale range for that material in that condition. It says plainly when the photo cannot decide, which with coral is often the difference between natural and dyed Corallium or between coral and dyed shell, and it names the photo that would help, usually a sharp close-up of a drill hole and a cut end. It identifies and estimates. It never authenticates, never issues a lab report and never vouches for the species or the legal status; a gem lab with the piece in hand settles the valuable strands and carvings.
Common mistakes
- Treating a uniform, perfect red as a sign of quality. Natural coral is slightly uneven; perfect uniformity points to dye or plastic.
- Scrubbing an old strand with a brush or soaking it in cleaner. Coral is soft (about 3.5 on the Mohs scale) and acid-sensitive; soap, perfume and sweat dull it over decades.
- Assuming "Italian coral" on a tag means Mediterranean. Much coral sold in Italy is Pacific material worked in Torre del Greco, and much of the cheapest is dyed bamboo.
- Mistaking pink conch shell for angel skin coral. The flame pattern on the surface is shell.
- Selling by the piece rather than the strand. Matched graduated strands are worth far more together than the beads apart.
- Shipping black coral or reef coral across a border without checking the rules.
What to photograph
- The whole piece on a plain white background in daylight, with a coin or ruler for scale.
- A close-up of two or three beads, or of the carved surface, sharp enough to show grain. This is the photo that settles most cases.
- A drill hole straight on, close up, where dye rings and bamboo texture show.
- Any cut or flat surface, such as the back of a cameo, where the concentric rings would appear.
- The clasp, hook or mount with any mark, close enough to read.
- A view down the strand to show how well the beads are matched and graduated.
When to get it looked at in person
- A gem lab such as GIA, SSEF or Gübelin identifies the material, separates natural from dyed and bleached, and can often state the species group. Expect about $80-200. Worth it for oxblood and angel skin strands, large carvings and anything over about $500.
- A jeweler with a loupe and a refractometer can confirm coral against glass and plastic in minutes, and an XRF reading settles the gold in the mount.
- An appraiser or auction house jewelry specialist for Victorian and Georgian coral, Japanese carvings and fine cameos, where the work and the period count. Our guide to how to tell if a ring is antique covers the period clues, and the organic gem logic here is the same as for pearls and amber.