Coral is a tree/rock-like deposit consisting of the calcareous skeletons secreted by various anthozoans. Coral deposits often accumulate to form reefs (coral reefs) on islands in warm sea. The red-orange, pinkish, or white deposits secreted by corals used to make jewelry and ornaments.
It is like a plant consisting of only trunks and stems, without leaves and flowers, which live and grow under the sea water. These is where small newly born fish hide against their hunter. The trunk is about one inch across (maximum) while the stem is about 2mm across(minimum). Diver picked the whole plant and sawed them to cylindrical pieces. Drill each piece of cylinder a hole in the center passing through the other end. Polished them and then use a plastic wire (fishing line) or dental floss or gold wire or any thread that is strong enough, to pass through each hole of cylinder to form a bracelet or necklace.
Every country have coral reefs under their seabed. So you don't know which country the corals came from. When we say they come from that country we usually meant they are cut, polished and drilled there. I think here in the Philippines no one know how to cut and drilled hole on them.
Source - WEB