The Real Deal: How to Tell if Your Gemstones Are Genuine – Part 4 – Coral

As anyone who appreciates fine beads or jewelry can tell you, coral isn’t just a fancy kind of shell. In fact, it’s not a shell at all! Coral is, by Google’s definition, “a hard stony substance secreted by certain marine coelenterates [aquatic invertebrates] as an external skeleton, typically forming large reefs in warm seas.” This so-called “organic gemstone,” (the other main ones being pearls and amber) has been a highly-coveted material for millennia; in addition to large, high-quality, in-tact pieces being relatively hard to find, it also comes in a beautiful array of different natural colors and textures that aren’t found in other natural materials.

Bamboo coral, a heartier coral that is often white, is often sliced, dyed, and tumbled to look like pieces of extra-large branch coral -- which doesn't actually exist.

These coral beads were made from bamboo coral, a heartier variety of white coral that is often sliced, dyed, and tumbled to look like pieces of extra-large branch coral. Photo courtesy of mamasminerals.com

Unfortunately, as is true with most highly-desirable gemstones and the like, coral is very commonly enhanced and/or imitated. Although many beaders are completely fine with using enhanced coral in their jewelry creations, most at least want to know if the pieces have been dyed, heat treated, or otherwise messed with. We did some research and found out what makes coral valuable, what are the most common forms of coral manipulation, and signs to look for to indicate coral tampering (depending on the color of the coral).

What makes coral valuable?

These blue sponge coral beads are most likely a natural coral, but they've been stabilized with resin. Photo courtesy of OzBeads on Etsy.

These blue sponge coral beads are most likely a natural color, but they’ve been stabilized with resin to make them easier to shape and polish without crumbling. Photo courtesy of OzBeads on Etsy.

Coral comes in a beautiful range of colors, including: light to dark pink (especially popular during the Victorian era), medium to dark red (the most sought-after internationally), white to cream, yellow, orange, blue, purple, black, gray, and dark brown. (jewelinfo4u.com) Different types of coral can range from semi translucent to opaque. The coral of most interest to jewelers is called precious or noble coral, Corallium rubrum,which ranges in color from pale rose to dark red and “grows” in branched deposits. Precious coral is harvested almost exclusively in the Mediterranean off the coasts of Italy, France, Spain, Algeria, and Tunisia. Other types of coral are pulled from the waters off Malaysia, Japan, Australia, Africa, and numerous Pacific islands. (collectorsweekly.com)

A sample of highly-coveted, deep red branch coral. Photo courtesy of ethnology.wordpress.com

A sample of highly-coveted, natural deep red branch coral. Photo courtesy of ethnology.wordpress.com

A beautiful example of a carved natural coral cameo. Photo of pendant courtesy of faycullen.com.

A beautiful example of a carved natural coral cameo. Photo of pendant courtesy of faycullen.com.

There are two things that have made coral attractive to jewelers for so many centuries: 1) it is a relatively soft material (compared to, say, quartz or another hard mineral), which makes it a popular material to carve into cameos and 2) it used to be available in a seemingly inexhaustible supply. Thought by the Romans to protect children, today we can plainly see that coral itself needs to be protected. In today’s legitimate jewelry-making world, only the corals that grow slow and live long are selected for jewelry and other ornamental purposes.

Unfortunately, despite careful preservation, coral reefs are among the most threatened ecosystems on the planet, dying off at an alarming rate. Pollution along coastlines caused by run-off into the world’s oceans is the biggest killer of coral, followed by damage caused by boats (commercial fishing, careless boaters, etc.)  In addition to conservationists working tirelessly to ensure only legal reefs are harvested and that other wild reefs are preserved, there are also groups (namely in Japan & Hawaii) who are developing pilot programs attempting to create coral “farms,” the perfect places to harvest coral to meet the needs and desires of the public without damaging delicate wild coral. (www.bwsmigel.info)

How & why do manufacturers manipulate coral?

Since natural, deep red coral is the most highly-coveted type of coral, it only makes sense that it is the most likely to be imitated. A lighter coral with lots of bumps, pits, and other unsightly flaws won’t fetch as high of a price as smooth, mostly blemish-free, true-red coral. But buyers, beware! Some of the sneaky tricks that manufacturers pull can be hard to spot.

Natural, unadulterated branch coral possesses a distinct pattern of parallel stripes with a slight variation in color and transparency. One blatant sign of a phony piece of coral: bubbles! No matter how deep the red color, if you see bubbles in a piece of supposed coral, what you’re actually holding is either glass or resin. Imposters made from other types of plastics are also be fairly easy to spot, since it is difficult to completely remove the molding lines from plastic cabochons or beads.

This sponge coral cabochon would have to have been stabilized with resin to be carved so smoothly. As for it's color -- it's hard to say with photos on a computer, but our guess is it has been dyed. Photo courtesy of wanelo.com

This porous sponge coral cabochon would have to have been stabilized with resin to be carved so smoothly. As for it’s color — it’s hard to say with photos on a computer, but our guess is it has been dyed. Photo courtesy of wanelo.com

Another helpful hint: look for small white flecks and patches on and inside the gem’s surface. If a blood-red piece of coral has no such irregularities and its price seems too good to be true, then it’s probably synthetic. (collectorsweekly.com) We don’t happen to think non-red coral is unattractive — white coral and light pink coral, even with dark patches, still has a cool, earthy quality. What we DO object to are folks passing off lighter-colored coral that has obviously been dyed a deep, bright red as the “real deal.” This is very common in thicker, chunkier coral beads, and frequently the dark patches on the beads (which are also often lumpy and irregular) have been filled with resin to stabilize the more brittle varieties of coral. The same goes for the more porous sponge coral; although not always dyed, it’s porous make-up makes it brittle, so sponge coral beads manufactured for sale are frequently injected with resin to stabilize them. We have no problem with stabilized or dyed coral beads in general — we sell them fairly regularly in the shop! — but we ALWAYS inform our customers when the coral has been modified.

For a beautiful variety of photos of amazing pieces of antique and vintage coral jewelry (like the carved cameo pictured above), check out FayCullen.com.

To find out more about the legality surrounding the buying & selling of coral, check out this website. We understand there are artists who prefer not to use animal byproducts (bone, leather, etc.) in their work for personal reasons, but for those who do, and for all readers & beaders in general, we hope you have found this blog post informative. Happy beading!

Check out more tips & tricks in identifying beads of different materials:

Part 1 – Turquoise
Part 2 – Amber

Part 3 – Bone

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