Ah Hans, you have hit my favorite subject. I can talk for hours about
black coral but will try to be brief.
First, black coral is considered a ‘soft’ coral, meaning it is not
hard like the stony corals. (Won’t get into all the reasons behind
this and the taxicology and science which is very confusing). There
are a number of kinds of soft coral but black coral is an anomaly
because it isn’t really soft…it is, as you mentioned, a horny coral.
It is mostly protein and unlike stony corals in which the animal
itself becomes part of the structure as it dies, black coral is
actually the skeleton of the animal. The animal itself simply falls
off when it dies.
There are two types of black coral. Though both are made of the same
protein material they have some different physical attributes.
Antipatharian black coral is deep water (primarily below 100’) while
the Octocoral is shallow water primarily above 100’).
Antipatharian is the harder of the two though not necessarily more
dense (SG around 1.25). Once dried it cannot be re-wet (?) and formed
without great difficulty. It is more easily ground into cabochons or
carvings. In ancient times black coral was believed to protect one
from disease, hence the name - Antipatharian. Because it is from such
deep waters, it is difficult to obtain. It has been reported that in
1996 two divers died in Hawaii trying to get to deep water
Antipatharian coral. Thus, Antipatharian coral can be very very
expensive. It is found throughout the Pacific, around India,
Australia, the Red Sea, the Med and Caribbean.
Octocoral is softer (SG around 1.20). It is very plentiful around
South Florida and the Carribean, often found in piles washed up on the
beaches. After drying, it can be re-wet and tied into knots like
spagetti or bent into bracelets or earrings. It can also be bent by
heating it. Despite its availability, only a few people work with it
extensively and thus, it is still fairly expensive though nothing like
Both types take a beautiful polish when worked properly but
Antipatharian is the more durable in that respect.
IT IS ILLEGAL IN THE UNITED STATES AND MANY OTHER COUNTRIES TO
HARVEST LIVE BLACK CORAL WITHOUT A SPECIAL LICENSE. IT IS A PROTECTED
SPECIES. IT IS NOT AGAINST THE LAW TO COLLECT BLACK CORAL FROM THE
For more see the August 2000 edition of Lapidary
Journal. If you want more on how to work black coral,
contact me off-line at @coralnut. I will send you a six
page description of the process that didn’t get published in LJ due to
Cheers from Don at The Charles Belle Studio in SOFL where simple
elegance IS fine jewelry!