No. Coral itself is a kind of living organism related to jellyfish and sea anemones.
They do build shells made of calcium carbonate, however, which is a calcium salt.
A non profit society that gives consumers the truth on coral calcium. The address for the Coral Calcium Watchdog organization is: 2718 Lexington Woods Drive Spring, Texas 77373.
calcium
why do coral reefs can live in salt water
Yes, coral does have exoskeletons made of calcium carbonate. These exoskeletons provide structure and support for the coral polyps, which are tiny organisms that secrete the calcium carbonate to build the coral reefs. Over time, these exoskeletons accumulate and form the large coral reef structures we see in the ocean.
Calcium
When a coral polyp is formed it takes in the algae and the algae carries onto photosynthesis inside the coral. The algae later helps the coral change calcium salts in seawater into a hard calcium carbonate structure that makes up a coral reef. Without the algae helping to create calcium carbonate, a coral reef wouldn't have it's nice structure.
Calcium sulfide is a salt.
Sea salt doesn't contain calcium silicate; calcium silicate can be added to salt as an anticaking agent.
Calcium and salt
The salt formed by the reaction of calcium hydroxide and sulfuric acid is calcium sulfate. The formula of this salt is CaSO4. Calcium sulfate is a white in appearance when pure.
Calcium Sulphate is an alkaline salt.
Calcium and phosphorus